I dont know what you mean by gimbals, but I have not had any adverse effects. I dont see why it would, being Pioneer designed that switch there themselves. People have actually had to solder two points together on the N1's and N2's to bypass the unit, and some people here have been using their bypassed units for years. I think Pioneer put the easy switch in the N3 to comply with federal law, but making it easy for the individual to bypass the unit themselves. Im guessing that when people realize how easy the bypass would be, they would want to purchase the N3, hence more sales for them.
As for the buzzing motor sound, I believe that is the DVD drive accessing the Nav disc.