I think it's weird as hell not to include characters that, in previous games, had a COMPLETE move set. The games should allways include past stuff. If Hina, Mr.3, Bon, Shanks, Lucci, Ohm, Enel, Foxy, Arlong, Kuro, Krieg. . . . . .and MANY others where playable in previous games, why not this time? The roster is certainly small taking into consideration that chracters play more or less the same.
Also, the gameplay mechanics require a change. The chains are all pre-made, there's little variation in what you can do once you start a chain (^attack, ^attack, ^attack). And if support characters have to be like this, then off with them. There's some of them that are directly offensive (Shanks appears. Spends 5-6 secons SLOWLY walking. Takes the sake. Pours it in the glass. Drinks it. THEEEEEN, he SLOWLY slashes. Thank you, Shanks! You helped big time!) In JUS they where good already.
So, better gameplay, tweek the support system, more battle characters (why can't I choose 2 fighters? why 1 + 3 f*cking supports?) and a MUCH better roster.