Yeah they can be quite dangerous in the wrong hands. Spectra fibre or Kevlar lines stretched taut are very capable of causing severe injuries. Those kites can move at a pretty serious clip and things can get hairy fast.
"Practice makes perfect" or at least it can keep everyone safe. I've been around beginners and they always made me nervous. Good luck and watch out for the ones that aren't watching out for you.
Nice foil! Are you using it for traction (buggy or board)? Some years ago I was into stunt kites and even made a few. Hmmm... Maybe I'll go dig them out...