1 &2) Yes trim & bolts need to be removed and the line will almost split the spear bracket screw holes.
3) Depends. If the car was from NOR then will probably will not see as much overspray on the underside of the car due to it being just a few feet off the ground and truthfully the fenders would come off as well to do the spray on the lower cowl or tulip panel area as seen in James' photo.
If it was built in LOS then you would have more (or should I say potentially see more) overspray due to it being held from an overhead conveyor system.
Also remember that the subframe, brake lines, etc would not have been there when this was painted. If I were doing this I would tape off on the inside weld seam lip and spray that area. Removing fenders to get that area covered would be up to the individual.
Someone please correct me if I am wrong.