I don't think you really covered the main concerns about gameplay. I talked with Dahbomb and he showed concern about the lack of a lock-on limitating your moves (like for example High Time HAD to be mapped to B because you couldn't do back and Y because it would be forward Y with the auto lock on system that would lock to the enemy behind you) and the lack of just-frame mechanics, since the game is 30fps, it would either be a 2 frame link (wich may not seem like but for everyone who plays fighting games, you know that 2 frame links are WAAAAY easier than 1 frame links) or the game would have to be pretty slow compared to the other ones for you to be able to react in one frame at 30fps. If it was fast and still a 1 frame link, it would be pretty much impossible to use it at 30 fps.
Another concern is how easy it is to stay in the air, but that I won't even comment because the way I see it it's just a different take on the gameplay, not necessarily bad or good. But the other ones are valid concerns, and I'm concerned as well. But, in the other hand, it can be a concern when you think in the lines of: Ok, so the game has jump cancel, so what? You can keep attacking and you'll stay in the air anyway, what difference does that make? In previous games jump cancelling was required to stay in the air, in this one it seems like it's there just to say "look guys, we have jump cancelling back, it will be hardcore". I'd rather see they actually showing us why it is hardcore. They said multiple times that they don't care about people whining because of design changes, and yet that's all they show and talk about, show some skillful gameplay then, I'm sure at least the gameplay concerns they are interested about, since they invited a pro DMC player to play the game in their offices and provide feedback.