Actually I would speak with the hotel mgr and tell him that although you enjoyed your stay very much, there was one thing that surprised you because it seemed so unusual, and then tell him exactly what you told us.

I sometimes tip shuttle bus drivers and sometimes I don't. I don't really think I have a pattern or a rule, I guess it depends on whether I carry my luggage, whether he opens the doors/is generally helpful, tells me about the area/gives an informal tour, etc. I never tip drivers who talk on their cell phones while driving -- I find it unbelievably rude (as well as dangerous) and it annoys me when they do it. (of course calling the hotel or dispatcher is okay, I'm talking about personal calls).