Basic Magic
simplify the basic magic system skill to just white magic skill and black magic skill. Yes, that changes a lot but really, seeing that blue magic, ninjutsu, bard songs, etc cover a WIDE variety of effects in their purview, it would make things a bit more consistent. Would save everyone a lot more space as they wouldn't require nearly as many gear sets to accomplish their job to a respectable degree.
Partying in General
At any level, there's so many mobs that are not even approachable for EXP as they have so many nasty moves or are just generally tough whereas other mobs are almost impaling themselves on your weapon and in either case they both types will give the same amount of EXP, assuming that they are the same "level" of difficulty. Make tougher types mobs give inherently more EXP; they are more dangerous, you should be gaining
substantially more for defeating them. If they'd use a system reminiscent of
http://www.returnergames.com/ord/ind..._Two:_Monsters for monster creation, I would be very pleased (I recognize the scales of FFXI and FFRPG are completely different but having a similar monster design pattern would be nice). This might help generate parties at higher levels that aren't primarily melee burn, if the exp difference is considerable enough (I mean, one should get at least double the exp for defeating an Malboro than I would for defeating a Colibri of the same level, as the Malboro is inherently more dangerous).
I'd also like see partying against multiple opponents more viable as that would give AoE spells and attacks a better name then simply being a hazard to avoid.
BLM
Make the elemental spells of the same tier have the same mp cost and the same damage scale (i.e. casting thunder would yield the same amount of damage as casting earth on a mob that was neutral to both, both of which would cost the same mp). I should
NOT be able to do MORE damage with a higher level spell of the same tier that the mob is neutral to than the spell of the element the mob is weak to. The corollary to this is to rebalance the mobs so that there is a closer to having equal share of mobs weak to each element. This would also hopefully breathe some more variety in what to merit instead of only focusing on Ice and Thunder.
Also, I don't know about you guys, but I'd be more than willing to trade a few levels of Clear Mind for some enmity down traits and a few levels of Auto-Refresh that are innate to blm (that said, i think any job that uses MP should get Auto-Refresh at some point).
SMN
To encourage smn's to use their pets more, change the perpetuation system. Instead of having pet be available for as long as the summoner has MP, change it to the avatar can be out for (60 or some other static base value + summoning skill) seconds, using the value of the summoning skill value that they were summoned with. This would allow a summoner to have a pet out to help and still do other things! Bloodpacts would still require MP, but now the burden of the perpetuation cost would be no more.
That's all I can think of for now. Will post more whenever the muse strikes with more inspiration (need more Glamour!!!).