I don't know how you could see a line on your arrow very well. Only one way to find out...
Back of the point works well for me on selfbows where I don't have a clicker. But better with broadheads than field tips. Sometimes, the transition from shaft to tip is so smooth, I can't feel it. Yes, your gaps will widen considerably. It's just part of the compromise.
I like clickers. But if you're trying to win at 3D, then do a feather to the nose or some other trick to verify your draw. If you're not trying to win, then do whatever you want. If you have no intention of winning and are just out to practice for hunting, who cares what the technical rules are?