Oh, I just remembered a few I forgot:
7. Let us keep the abilities gained from Dream Eaters
You would think the game would encourage players switching out DE & trying them out but instead it's the opposite. The player is actively punished for removing a particular DE from the party by taking away associated abilities. This more or less forces the players to stick to particular DEs for certain key abilities & ignore the rest.
But even then there's no such thing as an ideal party. No combination possible will give you
every ability, which seems very unKingdom Hearts to me. Afterall BBS lets players have utterly maxed out characters if they put the work in it. This is especially problematic with status effects protection. Quite frankly status in this game are as diverse as in 358, most are just minor variations of "make the player not move". As such, the player may be protected from 1 or 2 statuses, but there is always at least 1 that stops them dead in their tracks. Really infuriating.
8. Disney characters either as guest party members or on-field NPCs.
You ever noticed that after the story is done, the surviving world inhabitants are actually nowhere to be found? Most games would have them wandering around certain areas & would chit-chat with the player but in DDD they're nowhere to be seen. I guess this could be an aspect of the dream world setting but really it's just a jarring design oversight.
Additionally, DDD is a bit lacking in side-quests. To kill 2 birds here I think they should take a page from RE:Coded's book & have the NPCs give the player world specific side-quests to carry out.
The fundamental downside to DEs has always been that they replaced normal & guest party members. Quasimodo, Pheobus, Quorra, the Musketeers, Sorcerer Mickey, of course Neku were all prime candidates for in-gameplay allies & the fact that none of them were is a big waste.
I wanted a Mickey storyline even in the original BbS,
Well he is the only other character on the cover besides TAV. Hm, maybe a RE:BBS R/R with both Mickey & Vanitas story modes...