Quite a read there but entirely valid.
I've seen the Tigermoth with sole pilot at Moorabbin, however he uses chocks. Set throttle, place chocks, mags on, hand start, walk back, adjust throttle etc as required, warm up engine if required - remove chocks with rope, enter cockpit. (he doesn't remove the chocks when inside the aircraft)
Much safer, but still not perfect. One would assume that the passenger does not have access to the throttle so this would be quite a safe operation.
I've done a hundred or so starts on the Tiger as the right-hand-man, can highly recommend it for the purposes of a safe operation with a quick turnaround, but I'm sure there are other ways to do it safely as a sole pilot which would no doubt include a long rope.