I second your idea of getting rid of Heyman and turning Punk back into that character. Not a Face, but not a full on Heel. What I have noticed with WWE, their image of a "super heel" is someone with no personality. Not saying Punk's current character doesn't have personality, but it is very watered down from what he can do.
When they gave Jericho a huge heel turn, no personality, just very serious. Randy Orton, no personality (and still none
). WWE needs to just go for it and not make their characters so fucking stale.
Give Punk the microphone and no script and let him do his thing, ratings will fly.