@Zero This depends on how much effort you want to put into maxing out your jobs. If all you're looking for is enough to complete the game, you may not be able to set up some of the more powerful builds available. You should try to max at least two jobs for each character, so that you can use all of their abilities and skills as both your primary and secondary jobs. I didn't use Spell Fencer much as it seemed only good for support, I felt like I could do better with more offensive classes. It can be okay as your secondary job though. Here are some I'd recommend for their base abilities:

Knight
Knights can be great if you find yourself needing some more defense for survivability. When you max out a knight, you can then equip them with two shields, giving them excellent defense to protect your party. Although you won't be able to use most attacks, you can still use one called Super Charge which uses your defense stat as the base attack power, allowing you to get in a few strong blows now and then. You may be tempted to switch to Templar over Knight, but, their abilities and offensive are not as good.

The dual shield skill can also be useful for a dedicated healer in your group.

Monk
Monks are great at bringing the pain, but at the cost of lesser defense from not being able to use shields. They do however gain some HP-up skills, which can be useful in any job. Even their normal attacks can be strong, but they also have some good damage-dealing abilities as well. Just make sure you keep them safe with healers and if you're using a knight.

Swordmaster
This class is a little more situational, but it can be very powerful if you figure out how to make the best use of all its counter abilities. It can also be interesting to mix with Ninja: see below. Plus, its final skill is a great one: abilities use no MP for two turns.

Thief
This is good to have as a secondary for someone to steal good stuff, though you may be past the point where it's easier to level it as a main job.

Performer
This is probably the best support class in the game, though is probably best used as a secondary when you can. It's filled to the brim with various types of stat buffs, but what really makes it great is its final ability, which raises the BP of all other party members by 1. If used probably, you can really get a lot of extra BP out of this!

White Mage
You'll definitely want to max this with at least one character, but preferably two. In some cases, you may want to have the white magic set as your secondary abilities with a offensive magic job in addition to another character as a main one. After maxing White Mage, you will want this character to switch to Spirit Master as the main job with White Mage as the secondary.

If you're going to go the extra mile and max more jobs, you'll want some of these at least:

Ninja
Everyone should use Ninja at some point, if for no other reason than Utsusmi! This wonderful ability allows you to evade any physical attack without fail. What's more, you combine this with its skill in Transience, and you'll counterattack whenever you evade. Plus, mix this with the Turn Tables from Red Mage, and you'll even recover BP from the dodge 'n counter! This can still be a useful job as a main on its own, but is best used combined with other jobs as a secondary.

Red Mage
You'll want this as stated above for using Ninja, for its Turn Tables ability to give you 1 BP for every attack evaded. It also has another good BP-building skill in Revenge, giving you a chance to gain 1 BP simply from taking damage from any attack.

Freelancer
It will take a while to max this job as it requires more JP than any other, and has low stats. If you do however, its final ability may yet be the best in the game. This one also gives you the skill Job EXP x1.2, so it can help you max out jobs faster as well. In any case, its final ability is Mimic which allows you to repeat the last move used from your party (including the user) at no cost whatsoever. This means no MP used for spells, no item consumed for an item, no extra BP used for a move, etc. The best use of this ability however is to use it after your Performer uses the My Hero ability, which is the one that gives 1BP to each member but the user. If you combine it like this, you can easily get your whole team to 3 BP in no time! This job also goes well as a secondary for a dual-shield Knight, as it also has a few other support type abilities and there's little else such a Knight could use.

Conjurer
This won't end up being a class you'll want to use, but rather it's how you learn some great skills to use for other jobs. Steady MP Recover gives you 30 MP every turn, great for your healer(s); Max MP up by 30%; EXP gain up by 150% if you still need to grind, and of course, Obliterate which will instantly defeat weaker enemies at start of battle (unless you were back attack'd) making it great for grinding more JP.

I think there are some other very useful jobs and combos, but I forget at this point.

Wait Spell Fencer isn't that good? They seem to get the best attacks for me and you don't have to waste a lot of MP to use them since once they put a spell on a weapon it lasts like 5? turns.

What is a maxed out job? Most mine seem to max out at level 11?

@Zero Spell Fencer is good if you don't want to grind for one of the more powerful setups I talked about, especially if you use it as a secondary for Swordmaster. I just didn't use it that much.

14 is the max level for a job.

Hmm, 2/4 of the way through the annoying end part. Hasn't been too bad so far, do the 4 main bosses ever get much tougher? I mean, they keep getting tougher, but it doesn't seem to be significantly tougher?

On the other hand, all of the previous bosses you fought before who are back now seem to be WAY tougher on the 3rd part. They all have partners and stuff now?! I can't make any progress on any of them without getting instantly obliterated. Ug. Is it necessary to fight many of them or can I just focus on the main 4?

@Zero I don't think that any of the four crystal bosses change very much in the repeating chapters. Maybe some slightly higher stats each time, but they are mostly the same, if not entirely.

Everything else in those chapters is optional, so you don't have to do it if you don't want to. They get really tough, far more than anything else in the game save for the secret super boss. You really need to have created optimal setups if you want to have a chance.

@Mop it up But if I skip most of the optional stuff am I going to be totally screwed at the end end? That's my main concern.

@Zero Screwed in terms of what? There's not much you'd get from it that would help you out anyway. I felt like getting to character lvl 99 was enough to make the non-optional stuff a breeze, so it should be possible on even lower levels too.

I mean if I skip all of the extra stuff and just focus on getting to whatever the TRUE END BOSS is, am I going to be uber under-powered? I'm still around level 60 right now...

I find that job setup is generally more important than character level, so it's tough to say. With the right jobs, you could get through at 60, or you can brute-force at 99 if you have poor job setups.

Looking back in the thread, people like Hero_of_Hyrule felt like they needed to level to 99 to beat the game, but I didn't feel like it was necessary myself, and I've read accounts of other players beating it at lower levels their first time including in the 60s. It's even possible to clear the game from start to finish at character level 1 for everyone, so it's really all about jobs. I guess I just found some good setups that helped me through with little problem.

If you find you can't make it through with your current level and jobs, there will still be opportunity to battle and grind, so you won't be screwed in that sense.

Well the first boss in the third set wasn't too bad, but the second one (the one that splits into 4 and drenches you with water) is destroying me. And I can't really fight any of the optional bosses since they are destroying me too, so I guess grinding it is? Ug.

So close to the end. And so far.

@Zero This game is decidedly old-school, did you not expect there to be grinding?

Fortunately, with the option to increase the encounter rate, and 4x battle speed, it doesn't take very long to grind. I think I went from the low 70s to 99 in a couple of hours. You can also bump the difficulty down to Easy if you don't want to grind as much.

I am on easy! And I hate grinding! Also you claimed you don't even have to grind levels just pick the right classes but now you say you grinded!?

The battles seem to take FOREVER though, am I doing something wrong? I remember reading somewhere about some class power or item or something that made grinding way easier but I can't find what I read now...

Ah well, grinding it is I guess.

@Zero I don't recall saying one doesn't have to grind, just that jobs are generally more important than character levels. There will definitely be some grinding in this game even if someone skips the optional stuff, at least for job leveling, and the amount of it depends on which jobs the person goes for. I always like to do everything I can in games so I reached lvl 99 before beating it the first time, though I didn't max out all the jobs until New Game +. I felt like I was overpowered for the main story though, so I feel like it could be done without reaching level 99 and other people did it. I had maxed out the main and secondary jobs I was using for my characters so I had some powerful skills at my disposal. I think I already mentioned all that...

In my big job post above, I mentioned that the Conjurer class gets a skill called "Obliterate" which will instantly defeat all enemies at the start of battle who are weaker than your party by a certain number of levels (unless you get surprise attacked). Maybe that's what you're remembering. I don't recall how many levels Conjurer needs to gain to earn the skill. Before I got that skill, I would just use my strongest attacks x4 on the first turn, which would typically defeat all the enemies, or maybe just one left, so it didn't matter that my characters would get down to -4 BP. I also gave them skills that increased BP for things like taking damage and receiving status ailments, so they would recover faster if there was an enemy left.

Yeah that is probably the one?

Too bad to get the Conjurer I need to beat a boss fight with three freaking bosses who just level me instantly ahhhhhhh.

All of my characters are at level 60 right now. Probably not the best level to be taking this stuff on at yet.

There is usually a trick or two to beating the bosses. I don't want to give away any techniques, but there's armor that nullifies certain elements that should help your current situation (if it's the boss I think you're on).

I assumed such a thing existed, but I'm too lazy to run around looking for it. Is it something you can just straight up buy in a shop?!

I can't remember, I think so? I ended up with four, one for each member of my party. You should have access to at least one by now. There's a strategy to that battle without the need of such item, but it wouldn't hurt to have it..

Yeah I got up to level 66 with all of my characters and got one of them up to 14 in the Spiritmaster class which gave her a power that nullifies all elemental damage for all party members for like 5 turns or something... made that boss a piece of cake! So I'm back on track now.

@Zero Not that it matters now, but Conjurer can be obtained in an earlier chapter.

@Zero Hooray!

@Mop it up Really?!

Whatever the case I'm stuck on that fight now (though it is an optional fight so I guess I could just skip it, but I want that class!) None of the FAQs I am finding seem to acknowledge that there is a Yulyana boss fight where he has helpers! He's not even the tough one in that fight, the girl with him does "Susan-O" and even when I'm at full health it pretty much instantly kills like 2 or 3 of my characters and the surviving ones have barely any health and die before I can do anything else anyway.

I feel like there must be some trick to that spell, because no one else does much damage to me in that fight so I don't think it is supposed to be THAT hard.