No you don't have to be a Rocket Scientist to properly mount bindings. That said, I don't recommend it if you don't have the training.
A few years ago I went to the certification course to be able to safely mount bindings. (I've been to two such courses.) This was for an organization I volunteered at. We had a bunch of skis that needed to be properly set up. I mounted bindings and then did all
the safety checks on them. Using the following equipment:http://cgi.ebay.com/Vermont-CALBIBRA...QQcmdZViewItem
The Vermont Calibrator. There are two types of tests, a twist test to check the toe release and a pull test to check the heal release. You do three tests in each direction. I've tested bindings that were 2 DIN numbers off. (You mark these for future reference.) No skis left our shop without being tested. By the way, the Vermont Calibrator needs to be calibrated itself on a regular basis to insure it is accurate.
Any shop that does not test bindings is looking for law suites. The manufacturer's standard is to test bindings after you mount them. Most manufacturers require shop techs to attend the course I did to be "certified" to install their bindings. Shops are responsible for the equipment that goes out of their shop up to the time the end user screws around with it. (I almost always turn down my DIN setting thus I assume the liability, but that's another thread.)
Also, it it smart to have your bindings checked each year at the begining of the season. Parts wear, some bindings need to be lubricated properly, and rust can happen.
I've actually found problems with the way my bindings have been mounted and let the shop know that I was not pleased and had them correct the problems. (Hey, when you buy a new set of skis they better be set up correctly.)
So, I have no problems with people doing their own thing with their equipment. Just as long as they are informed on what can happen.