Ok, so it looks like airdodge no longer affects trajectory at all, just gives you invincibility frames during your jump. If you can jump after it, that means it can probably be jump cancelled. I expect it to only by able to be done once.
Also, anyone that wavedashes habitually will have habits to break. I mean, if I dash in close to a Fox, and he charges an up-smash, I have the wavedash backwards instinct. What else are you going to do, jump? Roll back? Shield then be stuck in his range? Meh. I'll accept the "it's a different game" thing for now.
Also, about the footstool hop/quick jump thingy:
From what we've seen, I think the "Samus on Sonic" FSJ is the first we've seen done on a grounded opponent yes? So probably, it sends you much higher. Also, it doesn't change their movement at all (almost like Mario's Cape). So this fact combined with the fact that Spindash charging PROBABLY has invinicibility, or at least "no flinch" frames, it's pretty much self explanatory, I guess.