The problem with this is that most players have a hard time judging a parallel line. There are ways to improve staying parallel, but I think you may as well just go to the "spot-on-the-wall" method:
You're right about that Bob. Most players who begin to use this method make errors with the parallel to the cue ball. There is a double check which can be used to assure the correct line but practicing this system will help too.
I like the spot on the wall technique too, but the spot you choose must be a certain distance from the table or the system begins to fail at some point.
That being said, if you have an accurate point of reference, banks and kicks becomes easy.
Tom