RE: How to handle the guys with flawed plans?
TBH, I can't see anything to get upset about.
For myself, if a prospective student doesn't want to play "on my terms", then we don't play at all. I don't have any problem with telling someone that I don't want to fly their plane for them; or teach them how to fly. Gotta learn how to say, "No" and walk away.
I must add that it is rare that I bother with instructing, nowadays ... 'cos I'm just not prepared to fly some bit of junk; since I'm responsible for the safe conduct of the flight.
Is that harsh of me?