Have you ever tried a "jack-of-all-trades" party in this game?

Have you ever tried beating this game with all the main characters practicing everything?
How did you enjoy it?
I have considered trying this on my next playthrough, but I am a bit concerned about the conflicting stat development and that I might find myself in a predicament where some important stats suck and it becomes hard to do anything about it.
Anyway, I have a feeling that a party like this might be pretty fun.

Of course, it may be a good idea to have the characters take turns practicing individual weapons, just so that they are more flexible and can use as many types of weapons as possible that are found in dungeons.

I've done it before and it's frankly not the ideal way to go about the game. Mainly because leveling up everything is tedious. The stat up/down grades are not a huge issue except if you're trying to max out things like Evade which are more difficult to level. Getting all of those skills to max on the other hand is just time-consuming, especially when magic gets involved, and certain weapons lose their usefulness since getting max stats will make their stat boosts utterly useless. Not to mention that making everyone good at everything makes the game rather boring. You'll spend half of it grinding and the other half waltzing over everything else with your unstoppable dual-wielding, Flare casting, death dealers.

Honestly, do it once to say you did, and then realize how specialization is actually more fun.

Thank you, I will think about this some more.

It's a bit hard to make the characters specialize in things so that they actually become well-rounded and useful, though;
I mean, if I were to follow the game's subtle suggestions then it seems that Frioniel is supposed to be a Red Mage (since he seems to be decent at everything), Maria an Archer/Black Mage (since she uses Bows and has a high Intelligence) and Guy a Berserker (since he uses Axes and has the highest HP).
However, this is more or less the party I am already using (although Frioniel doesn't use Black Magic), and the issue with that party is that I have a fighter as the only healer.
I also remember making Frioniel a pure swordfighter, Maria a pure White Mage and Guy a pure Black Mage, but that felt weird because I have always thought of Guy as the natural physical fighter.

I have considered having everyone learn the most important healing spells though, primarily Cure, Life, Heal and Exit.

Firionel was always more of a Paladin to me, his spirit stat is the highest of the final party. I usually sent him down that route at least but you could always just make him the White Mage if you're hoping for "pure" job roles.

Frankly, my party tended to always be a bit over-leveled, so I never really needed a full time White Mage. You could also make Gus into a Monk instead of a berserker.

First time I played it I had everyone with Cure but different weapons. Firion and Maria also knew offensive magic but of different elements I think.

Last time I played it I did more or less a simulated Class run. Note that Monk is overpowered in this game because Unarmed ignores defense from what I could tell.

But yeah, having everyone do everything is kinda boring.

I got curious and started a game like this a while ago, and so far it feels fairly easy.
I have just got the Mithril from Semite Cave and I haven't really had any problems yet.

One thing that I have done in order to make the characters feel more unique is that I have them prioritise their own specific weapons and attacks, and take turns practising individual things;
for example, Frioniel is practising Swords right now, while Maria and Guy stick to their Bows and Axes, and I will keep them that way until they have reached a decent weapon Level, possibly LV6 or something like that, and then I will have all of them switch to something else, making sure to have them practise their own individual things.
I also do the same thing with Magic - Frioniel mainly practises White, Guy practises Black and Maria practises the most useful spells of both White and Black.
This creates a kind of illusion that all the characters specialise in different things, even though they technically don't really have any strict roles.

Personally I have always thought that the basic Black spells in this game are fairly useful, so I make sure to get them as well;
Fire is great in the Ice Cave, Ice usually kills the turtle bosses in one shot, Bolt destroys the sea monsters, and Aero easily defeats the stalactite things on Dist, and Fire, Ice and Aero are also useful against the bosses in Mysidia Tower.