Bumping to ask: How am I supposed to figure out where the hell I should go on the License Grid? All I've got so far is that Penelo and Ashe are the best casters, and Balthier and Basch shouldn't be used for casting at all.
You can use anyone for everything, but I'd recommend you to focus 4 chars on attacking, while 2 are spellcasters.
Fran is a little bad at...everything, so feel free to leave her out.
I'd say Penelo and Ashe for magic(get 3 quickenings for them first and don't get any for anyone else, as they benefit from the 200/300% MP while others do not) and the other 3 for attacking...but if you want to use Fran, use her for magic and Ashe for attacking.
For spellcasters, obviously go for staves and mystic armor(possibly Main Gauche+a good shield for really high evasion), while the attackers should go for light armor until you can buy Shielded Armor, then go heavy all the way.
As for weapons, some weapons are slower, some are faster, and some use more than STR.
Only STR weapons: Greatswords(later on, but faster than shortswords for some reason), Poles(use Magic Defence instead of Defence, high evasion), Spears(some of the fastest weapons out there) and Shortswords(for some reason, they are seriously slow)
By far the easiest to do high damage with, just slap on Heavy Armor and go kill stuff.
STR+AGI: Daggers(fastest, I'd say that only Main Gauche is worth it for the godly evasion), Ninja Swords(fast, but they are only Dark+weak and 2 handed), Bows(slow, but long range)
Use a Cat Ear Hood to greatly boost the damage of these 3 weapon types.
Other:
Guns are by far the slowest, but ignore defence and your stats - the attack is only decided by the ammo and gun's power.
Katanas are STR+Magic based.
The other weapons are either gimmicky, random, or useless. Don't bother. Oh and rods suck, go with staves.
I'd say avoid shortswords and bows, as they are too slow.
I don't like guns, but you might like them.
Go with poles and spears, then later on use greatswords or mix it up if you want. Pure STR weapons are really the best in the maingame, except for some elemental stuff(Muramasa, Gladius)
Use Berserk. A lot. It gives a huge attack AND speed boost. Berserk 2, sit in the back with your caster throwing support spells and you shouldn't have problems(especially with an evasive setup). Even the game considers it as a positive status...probably the most positive one of them all.
As for your casters, early on they have little MP and spells aren't exactly excellent either.
You might want to ignore the attack spells altogether, as they are slow and Berserk outclasses them at no MP cost.
I haven't really used Protect, Shell and Haste either.
Obviously get Berserk, Esuna, Cura/ga/ja, Raise/Arise, Float...maybe Fira as Jellies are easy and fun chaining for lots of LP and gil.
License board - don't get unnecessary equipment licenses - if you don't have it, don't get it.
Focus your mages on magic based augments and rush 3 quickenings, as having 3x more MP is invaluable. You might want to get Berserk for your attackers and set it as a Self gambit to save MP. Ignore the rest of the spells and get quickenings after both mages get all 3 of them, then abuse Syphon to drain their MP for yourself.
Unlike the Sphere Grid, you can't screw up. Get 6 Golden Amulets and never put them away. LP is really easy to get. Just remember, augments first, then licenses for the equipment/spells you need.
Technicks...found them mostly useless too.
Steal is obtained by default, definitely get Libra...and ignore the rest. I find Charge overrated and the rest is gimmicky crap.