George:
By your numbers:
1: Unless physical damage is evident, I see no reason that it is not compliant. No, I have not seen anyone doing this around here. Professionals use a raceway. (EMT/PVC/etc)
2: Yes. As long as the MC is supported, and not subject to physical damage.
4: Protection by a raceway (EMT/PVC, etc) or any other suitable (to the AHJ) method I would guess.
