RE: Hinge gap
Yup - what GB and MinnFlyer said. I've tried hinge tape with a glow engine - didn't last long. Where I've had more than one color of film across the hinge line I use clear Ultracote. If it is one color then I just use matching color film.
If glow powered and the exhaust exits on top of the wing - cover the top to protect the backside of the seam from glow fuel. If it exits below the wing - then do the bottom.