Not quite in the spirit of admitting ignorance, but since it's in this thread, I'll answer it.

Did organized Objectivist activism, at least in some of its nuttier phases, offer to turn its adherents who get it right into a kind of superhuman entity? ...
another cult

No.

So despite Rand's disclaimer, if you view....

So despite what Rand or any Objectivist ever said or did, if you choose to view Objectivism as a nutty cult, you can.

If you were actually interested in why Rand's characters are the way they are, you could read her book on art, "The Romantic Manifesto". Probably a quick google search on the book would give you your answer.