Alright, here's my take on these points:
OP RHGs - people are fucking stupid, and usually never stick with one RHG anyway, people are gonna do what they're gonna do.
System isn't interesting - It's as interesting as you make it. What do you want it to be? A bunch of explosions and shit every time you click on an RHG page, or some bull shit like that?
More like an RPG - ...no. It's a fight. In RPGs, that'd be a lame-ass turn based battle. That's already happened once in RHG. Yoyo vs Chuck.
Fanboys/ biased voting - there's no way to really help that. People are going to vote for who they like, even if they see the animation or not. Because, again, people are fucking stupid.
People challenging others not on their "level" - there are no real levels, honestly. There's different skill levels, yes, but some people want a challenge, so why the hell wouldn't they challenge someone better than them? It may help them improve, and hey, if they win, that's a nice ego boost.
But that's just my take on things, feel free to ignore the shit out of this post.