I don't mind BJ's spitting image of Bowser. A lot of people say I look a lot like my mom when she was a teenager. But I too would like to see a game containing all eight of Bowser's kids.
"His alter ego Shadow Mario is redundant as an evil version of Mario, because we already had Wario."
Wario isn't really 'evil'. His greed brings out the worst in him. Personality wise, Wario is the polar opposite of Mario, but that doesn't really mean he's 'evil'. Besides, I always viewed Shadow Mario as a prankster, and Wario as a treasure hunter.
I see Shadow Mario to be redundant as a shadow version of the main character, because we already had Shadow Link in the LoZ series (.