I'm sorry, but I just don't see any of Dave Lovering's magic act in Nirvana's on-stage guitar-smashing antics.
In an interview he gave simultaniously with Rolling Stone/Spin/NME, Dave HIMSELF told Rolling Stone/Spin/NME that "I don't see any similarity between my psychic spoonbending, etc. and Kurdt Kobain repeated slaming his stratocaster into his fellow bandmates. I really don't."
So there you have it-straight from the Dave Lovering's mouth!
It's not so much the magic and the smashing, it's more the having an object in your hands and then doing something with that object while being on stage. See? See the connection?