Oh, and this:
Also how do mist abilites work?
They're called Quickenings:
http://finalfantasy.wikia.com/wiki/Quickening_(ability)
each character can purchase up to 3 Quickenings from the Licence board. In vanilla XII they cost MP to use, but in IZJS/TZA they don't (there's more in that link I posted).
You need to press R2 to roulette to a new skill once one is fired off, but there's a set limit of time, and every time you try for a new skill, the timer keeps going down.
Basically, the bigger chain you get going, the more damage you do, but the process is time consuming, boring and can be frustrating. They're a nice way to finish a boss fight if you're down to 10% HP or whatnot and are having a hard time. The animations are pretty though.
I must be strong!
Oh, and:
It's also worth taking speed of animation into account, as well as the fact that typically, male characters tend to combo more often than females. (iirc?)
Nah, there's no set rule for that. Combos are determined from the weapon itself, a character's HP (< 6.25% iirc HP combos more) and the Genji glove. To be exact: The weapon's combo stats and the Genji Glove increases the
chance for comboing, and the low HP increases the
number of hits.
Edit: Oh, but there is a thing regarding
time an animation takes. The girls take on average longer to finish the animation for a 12 hit combo. However they're not less likely to combo.
Time to finish a 12 hit (weapon unknown):
Vaan: 5.83
Balthier : 5.17
Fran : 6.13
Basch: 5.17
Ashe: 6.50
Penelo: 7.17
Which is why speedrunners doing Order of Ambrosia will use Balthier and Basch for taking down Yiazmat.
Sauce