A couple things that scare me:

1) Glow engines that start with a prop flip and no glow driver on (saw that). Be ready for them to start even if there's no glow driver. Keep the throttle at idle unless you're ready to go (kinda like "don't load the gun until you're ready to fire")

2) Folks at airfields pointing their 4-strokes AT ME while they start and run up the engines at the tables. That ticks me off... Heck, doesn't have to be a 4-stroke kicking a prop. Any plane could get outta hand and come at me.