The reason we have all those rules is that pilots have tried to do what the FAA (and, indirectly, Congress) clearly intended them not to do, and the FAA is always having to write more and stricter regulations to make it specifically illegal for the next person to do the same. If folks with PP's would stop trying to find sneaky ways to get paid by others for flying them around (which I have to say seems obvious to me as something that PP's are just not supposed to be doing), we wouldn't have all these rules and interpretations, and we wouldn't have to go through all this discussion. Remember -- Part 135 exists primarily because of Roger Peterson and his flight of The Day the Music Died.