Re: do i need a new bike?
If you don't want to harm the paint then you should put atleast some kind of thin barrier between 2 mounts and the bike. I used rubber, however most people here will ward you away from rubber as it has a tendency to break the studs. For some, it works fine.
If you ask me, I think a motor would look great on it.. Preferably a black one. You'll more than likely need a large down tube adapter though, the stock motor mount won't fit that bottom tube.