I must support Alanabit. I've never met Ozzy, but I do know his original manager, the person who first signed him, one of Black Sabbath's drummers, and his original producer and recording engineers, and I have heard countless first hand stories about him.
I can report that he really is just what he seems to be. He and his band paid their dues on the live circuit long before Alice Cooper was heard of. (and I won't hear a bad word about him either!)
Alice Cooper followed a long tradition of theatrical horror performers, like Screaming Jay Hawkins, Bobby Boris Pickett, Screaming Lord Such etc.
Ozzy was just the lead singer in an early heavy metal band. Most of the 'Prince of Darkness' stuff, biting the heads off bats, and the like was mostly accidental- and front men wearing eyeshadow was not unusual at the time.
I think the way that Sharon has built Ozzy, and the Osbournes into a marketable brand is astounding.
I wish I did know them!
Cheers
Dave