The girl in the orange tights (Dagger/Garnet) is really good. She does white magic and summons.
The ability system is great, they learn it off their weapons. If you want some tips, do NOT sell weapons you can synthesise 2 weapons together to make a new weapon. If you find yourself running low on cash early in the game, sell ethers (they're worth a fair bit and I found I didn't need very many) The steal rate is incredibly low in boss battles, it can be really hard to steal things.
The chocobo system is great in 9 IMO. They have "trance" rather than limit breaks which allow them to use stronger attacks once the gauge hits a certain point.
I hope you like the other characters, I never really cared for Zidane but he has some good moves. 2 summoners/white mages, 1 black mage, 1 blue mage.
Also none of the blue magic is missable, so don't worry about that. If you do miss some you can learn it off several different enemies for each spell and there's always a way. (Last playthrough I missed one and I equipped weak weapons and went back to an old area and got it easily)
Freya is great as well, she can often save your entire party with "jump", you'll see what I mean later.