I think he'd be a better dad than people expect him to be. he's still Cartman though, and he falls into the trap of wanting a built-in best friend that his own mother fell into with him, but at least in my heart and soul he's got a partner to rein him in. in lieu or terrorizing his classmates, he acts out a lot of his maniacal schemes on the PTA, which he has been kicked out of several times but still shows up to every meeting.

he also likes to play the "good cop" to his kids. reprimanding falls on his partner, that way he can be like "oh well, that was your dad's idea :/" later.

overall though I think he's a lovable papa bear who means well, despite being who he is. he has to be. for my personal id.