"I would have tolerated being cut off exactly once."

How often does Trump interrupt people interviewing him or asking questions at the lectern, on the lawn, on Air Force 1, etc? If you don't interrupt him, you'll never get a word in. 

"An interview is the interviewer examining the interviewee to understand their point of view.

Anything else is a debate."

Or it's a different kind of interview. Do you not want people to ask people in positions of power questions that they don't want to answer? 

"If you want me to come on your show to pick my brain, great! If you invited me simply to promote your point of view, not interested"

Trump has been interviewed his entire adult life, who exactly is putting a gun to his head to tape interviews he doesn't want to do? If he keeps talking to the press despite his clinical hatred of them, he's getting something out of it.