I've been mulling a few balance ideas over in my head for a while. One of my big criticisms of VI is that the characters blend together too easily, both due to similar equipment pools and the nature of the vocation system. To address the former, here is a set list I picked out to reflect the character's natures and for variety:
Hero: swords, bows, wands
Carver: claws, hammers/axes, bo staves
Milly: lightweight swords, fans, bows
Ashlynn: claws, whips, wands
Nevan: bo staves, wands, spears
Amos: scythes, axes/hammers, bows
Terry: swords, spears, boomerangs (keeps the orichalcum fang joke though)
Lizzie: fangs, axes/hammers, flails
This would require some weapons from later games to be added, but that ought to be easy enough on the programming side of things. Amos gets scythes because he's a good ol' boy, and because those things are wicked in VIII.
As for the vocations themselves, I think the merchant should be removed all together. I've never been short on cash myself in any playthrough, and the scant few good abilities it offers can be moved to other professions. Personally, I think Monster Masters and Rangers need the most work:
Rank 1: Soothe sayer, Squelch
Rank 2: Lullaby
Rank 3: Heal
Rank 4: Dig
Rank 5: Tongue Bashing
Rank 6: Weird Dance
Rank 7: War Cry
Rank 8: Puff
This is a complete overhaul to focus on animal husbandry, with all breath skills being replaced with either logical counterparts or removed outright because the free breath skills are over powered compared to the attack spells. This is a point of contention I see brought up by Japanese fans frequently, and it does make sense: why pay 6 MP to cast Sizzle when when Flame Breath hits higher and covers all enemies? Furthermore, humanoids breathing fire just looks dumb and that's why Level-5 moved all the breath skills to Munchie in VIII.
Ranger Status changes: HP:+10%, MP:-10%, Str:-10%, Res:0%, Agi:+20%, Wis:+10%
Special: Recruitment chance treats rate as if it were one higher, IE 1/64 to 1/32: Chance increases by one stage at rank 3, and again at rank 8.
rank 1: Safe passage, Vanish
rank 2: Midheal, Cobra Strike
rank 3: Mercy, Cock-a-doodle-doo
rank 4: Mist me, insulatle
rank 5: Moreheal
rank 6: Backdraft
rank 7: Call of the wild
rank 8: Brownie boost
This ranger is effectively an eco-ninja, with some of the jack of all trades style from IX. Vanish replaces holy protection but would work like Padfoot without the increased susceptibility to being caught off-guard, and Cobra Strike replaces Venom Mist to keep the poison aspect while making it more useful: instead of a group sweep it would use Kasnooze's accuracy rate on one enemy for almost guaranteed poisoning. Mercy would be a better Poof, in that it uses the normal 100%, 85%, 50% rates against all enemies. Mist Me replaces Defending Champion due to theming, and it's effectively the same result anyway.
Brownie boost is usually a super move, but I believe that making it a regular skill in this case would reinforce the nature theming. It gives a 25% attack, defense, and breath-resist boost. Superseded by oomph, buff, and insulate, but stacks with kabuff. Call of the wild would work exactly as Wolf Whistle does in IX, just substituting Agility for Deftness and using an animal appropriate to where ever it's used instead of forest doggos all the time.
The HP boost is due to a healthy lifestyle of living outdoors, which also accounts for Wisdom: you can't live in the wild for long if you're stupid.
Anyways these are just some ideas I spitballed around, and any feedback is welcomed.