I'll try to give you a basic rundown.
Hmmm... Gambit is the weakest link there, but he can get some meter for the team and maybe do some damage in the process. Also two anti air assists? Maybe Gambit(projectile)/Cammy(anti air)/Cyclops(anti air) can do better for now. If you learn to cover your assists properly(or feel brave) you can set Cammy as Cannon Drill assist(dont' remember the name, but it's the second one) to help Gambit better...
Gambit lacks good solo combos so you might want to stick to his standard bread & butter combo:
(jumping HP, jumping HK, ) crouching LK, crouching HP(launcher), superjump and standard zig zag pattern(LP, LK, LP, LK, HP or HK).
If your opponent doesn't roll when tripped, go for a (jumping HP, jumping HK, ) crouching LK, crouching MK, crouching HK(trip) cancelled(or "2 in 1") into Royal Flush hyper combo(qcf+PP)
and whenever you throw them dash and hit them on the ground with a crouching LK, crouching HP into an air combo.
On a vid I posted
here I go for an air throw because that does some more damage.
At the beginning of Royal Flush HC, Gambit throws his staff up, and if it hits it throw opponents back to Gambit's front, where the card throwing is going on. This way only a part of the cards connect tho, and it does less damage. At least you can combo into his launcher and then do the Royal Flush and then go for a DHC.
Cammy has a solid b&b combo with a crouching LK, crouching MK, crouching HP(launch), superjump into LP, LK, MP, MK cancelled into Air Cannon Drill(qcf+HK) cancelled into the Killer Bee Attack hyper combo(qcb+PP).
Again, if the opponent doesn't roll you can follow up with a dash, crouching LK, crouching HP into an air combo again.
Her Cannon Spike has invulnerability on the way up, but it sometimes stops going up and rebounds off some projectiles so be careful.
I've already covered Cyke's basic combos
here.
I hope that helps.