Let's get to the main highlight that for me makes this mod really cool: You did what other Addons rarely do and gave a new and improved moveset to modded characters like Silver and Shadow.
Now, for the criticism: You made all the cast very fun to use, yes, but every one of them got a bit of issues:
Sonic: Wall jump is very spammable, so much that you can regain the state even after the drop dash effect has activated on the ground, and then restart the wall jump like nothing.
Tails: Overpowered, period. You made Tails a king of verticality and ended up turning him into an airplane.
Knuckles: To be honest, the only general nitpicks I got with him is that his glide not having a some sort of delay feels really wrong, and his climb speed can be a bit hard to get used to.
Amy: Similar situation with Tails, Amy got a lot of verticality and makes her really overpowered as a result.
Metal: He's the one I disliked the changes the most, especially for how his moves tends to make sprites disappear and I don't know why.
Regardless of these nitpicks, this mod got quite the potential, and I hope it continues to improve and add more characters down the line.