No, no, no on the pressure washer....unless you want the decals to start coming off AND possibly have water forced into places it shouldn't be. Get yourself a hose, a bucket, some car wash soap and a long handled, soft brush and have fun. It also gives you the chance to see things like caulking and seal up close to check for problems.
Absolutely on the wax. If you've got a time crunch, at least get the front done so the bugs wash off easier. DH got a wax especially made for use with a buffer, but never on the decals....only by hand and use 303 for that.