Added 12 Volt receptacle and dual USB port

Nice install! Yes, parasitic drain is only an issue when you are dry camping and concerned about amp-hour usage and battery drain. The converter makes 12v all day when plugged in so no issue if you camp with hookups. Since we do a fair amount of dry camping, I installed a dual cig socket and I use one of the twin USB adapters that you plug into the cig socket so I can remove it when not in use.

RV wiring is unique...the 120v wiring follows the conventional color coding just like your house. Most of the 12v wiring in the TT seems to be like heavy gauge white zip cord, with a colored tracer run on the (+) side.