I said kamehameha too but by the attacks this will probably turn into a "biased" vote seeing as people will vote for whichever move their favorite character knows. You should add one of vegeta's attacks and a lot of others.
No, the disk is still pretty useless. It's got a nice surprise factor, try replacing your ki-blast with in for one shot while drifting in melee, but otherwise you're fighting some pretty poor players to get anything resembleing a good ratio going disk only.
Death Ball really is the better attack in most circumstances. Stronger and non-connected make it VERY spammable. KHH has the advantage of being available before trans, however, also making it useful. Fingerlaser rocks, but eyelaser is kinda crappy, so other than the fun value it has I don't know why you'd use it.
Smeg already knows what i'm going to pick . Other then that, I would say finger laser ftw, simply due that it can be effective during an attack on your enemy (a effective ki attack to combine with melee that's if i'm bothered to play as frezia though).