^Yeah forgot about the multiple Rider belt users
Now that you mention it, Accel's Electric slashes is in A form. What BanNam can do is change Electric into A-Slasher (complete with the A effect), speed it up, but remove the superarmor. Accel's Rider Art (Electric) just need the sound effect to complete it. Steam can be buttoned into Down+Special, while Air Special should be changed from Jet to Dynamic Ace (Engine sword beam) while Jet only appear when you're doing his Air Combo.
So, all of his skills can be included in CH:
Special> Rider Kick: Accel Glanzer
Forward+Special> A-Slasher
Down/Up Special> Steam
Rider Art> Electric
Air Special> Dynamic Ace
Air Combo Special> Jet
and also his slashing attacks while spinning, it's so badass to be left out. This can be his combination button attack.
And Meteor can also follow this pattern with:
Special> Jupiter
Forward+Special> Saturn
Down/Up Special> Mars
Rider Art> Starlight Shower
Air Special> Meteor Strike
while his tornado kick Meteor Strike can be his combination button attack (recommended Down+Weak>Strong)
Since Booster is playable in BW, there's a possibility of it been included in next CH. Even as Zeronos-type red gauge, i don't mind
Also, Birth need some upgrade too. Birth Gotou has a unique combi attack where he use Cutter Wing to cut the ropes that trap OOO while controlling it with Drill Arm. While his Rider Art should had been cut-scened, recreating the attack from where Gotou debut his usage of Birth Belt in tv show (he flies with Cutter Wing and then dive toward the Greeds and tackle them with Catepillar Leg and Shovel Arm)
Regarding Beast, I do want to see different playstyles with each Mantle equipped though that seems impossible...Beast is a butt-monkey even in the tv series. Even people who initially thought he's so overpowered in BW laugh at him as he DOESN'T have a bike and can't jump over a wall
Man, now I wish for a PS3 so that I can play BW and play as Accel and Meteor a lot >.<"" (had to finish my study 1st...)