On the longrun, I am a bit concerned about balancing difficulties. One argument was made that if character X was easy to play and as good as Fox, in a real game situation he will always be better than him.
Well, some characters have other layers of difficulty besides APM and timing precision, but still not every character is as hard to play as another one.
With the metagame evolving, the harder characters will benefit while the easier won't that much and it gets imbalanced again.
As example, take Jiggs as an easy character (sorry for the prejudice I know that character needs especially spacing, patience, pattern recognition, reaction and awareness but I have to make an example) and Fox as hard character. Right now, Fox is the better character. Lets say we nerf Fox and buff Jiggs to a point they are as good as each other at the current state of metagame. Fox will benefit more from the metagame evolving and suddenly Jiggs needs buffs / Fox nerfs again. If we do it the other way, nerf Fox and buff Jiggs to an amount that they will be as good as each other in 20XX, Jiggs would be op now and Fox really bad.
No matter how good the PMBR balances the game if they don't find a way to make the difficulties even / cause the metagame of different characters to evolve at the same speed, that balance will destabilize soon.
Fox still needs a few little tweaks, but thats not the core of the problem.