I think it looks sharp, very Tron like. Turn signal, I don't know. Drivers might not be able to see it from behind and at certain angles, or might not see it as a turn signal. And if you're moving your head around, seems possibly problematic. But try it out, and to be sure, ask random drivers if they understood it. Politely that is.

I wouldn't use glue, but get some industrial strength velcro tape. It will hold that, and would be easy to take off when you feel like riding less flamboyantly.