No it doesn't screw up the nail polish, just make sure it dries for a good 30+ minutes, and also dont use a lot of coats if your going to put tape over it, or else it wont all dry that fast. Also just use this link
It's recommended you use nail tape, however regular tape is okay. Before you put the tape on your nails, put it over your hand a few times to get rid of the stickiness. And when you peel the tape off, be very careful as it might remove some of the polish if it's still too sticky. Many people use regular tape to do nail art so you should be fine :)
it makes no difference
Yes it is bad.