Hey Waydown,
Not sure I understand what you are saying. You as pilot in command ( even if is not your aircraft ) don't have time to pre-flight the aircraft? You as pilot in command are going to fly a airplane that may not be flight worthy? You as pilot in command would stick your neck out and risk others safety and risk others equipment?

In my opinion I think you need to fly your aircraft and when you have time be the instructor/test pilot. If you cant do both on the same day, pick a day to instruct and test fly. It sounds like you really want to help others, that's great! But read your original post, what are you thinking?

Brian-