Interesting thread.
I'm guilty of using power tools during every stage of bow construction....and I have messed up some bows because of it. I have also messed up bows using hand tools. The difference being that if I'm using power tools, I'll usually mess up a bow after, let's say, 30 minutes....whereas if I'm using hand tools it may be 90 minutes before I mess up.
The trick is getting proficient with whatever you are using. Personally, I've tried everything from stone to state-of-the-art....but I tend to favor the power tools. Mainly because of the time factor.
The electric planer idea sounds interesting. I might get one eventually. I've heard only good things about them.