It's probebly not that hard but it's the time and work to make a piece like grant does I have some of they're stuff on my truck and I'll tell you it's a perfect fit and when finished all I need is some primer and paint.
it doesn't matter...it can go right down to the etch and cause problems later...no matter how much you sand it...you are best to do soft edges when priming....Oh and it looks killer by the way.