8. Doing exercises in the aisles or the galley
Wait, have you heard of that new fitness revolution sweeping the nation where you do yoga in the one space flight attendants have to do their jobs? Yeah, we haven't either.
9. Handing them a dirty diaper, used Kleenex, or Sprite can full of urine (again, true story)
Sure, it's part of a flight attendants job to walk down the aisle and collect empty cups and pretzel wrappers, but no where does it say they're the airplane's resident sanitation workers. Perhaps you put the can of pee back in your carry-on and dispose of it when you land, cool?
10. Scoring a free first class upgrade, then complaining about... anything
Seriously, you're pretty much playing with house money at that point. How about you just sit back and enjoy the warm towelette.