I really like Scourge, particularly his eventual break from his "evil Sonic" persona. He goes off and becomes his own person. This reinvigorates him, makes him better at what he does. He's snarky, and a bit of a jerk, but I've enjoyed just about everything with him in it. And besides, that's a cool design. And yes, I understand that he's technically a Moebian, but I don't really care.
Don't forget that they would've finished the whole Snively character arc thing. I just felt like this time he was actually done with Eggman. His character arc was nearing completion... But then they gave him a beard.
After the whole lawsuit, I think that Sega is trying to put some distance between themselves and the comics. I really wish they would though. I've actually been really wanting to do something like this on YouTube, but I haven't gotten around to it... my animator/brother tends to draw what he wants, which has nothing to do with this for the most part, and being thrown into college hasn't exactly helped the amount of time I can put into this. As for the actors list you have up there, looks pretty tight for the most part. But don't forget, it'd be nearly impossible to get all the voice actors back (or at least the ones that aren't still voicing characters in Sonic Boom/the games... I don't know who's doing any of that right now), so there'd need to be some recasting in place.