I think that you may be over thinking this just a little. First off there are alot of good "pdi" forms on this site. Some are more in depth than others, i would get the most detailed one possible. I would then get with your dealer and provide them with a copy of the pdi form so they know what to expect from you. The hardest I have found is for the dealer to have it hooked up to water.
I would have someone else take videos of the items you may forget how to operate. Like how to by pass the hot water heater. Or light the oven. As its your first I would take video of most evrything that you will have to turn on or adjust. You may want to take a video of how to hook and unhook from your vechile.
I do not think hireing a professional to look at things is needed.Good luck and enyoy your new TT
