Lots of Questions - So a few answers. I have a 28' TT
1. Yes we use ours on the road. Mostly in Rest Areas we will pull over for lunch, etc. We can put the slide out but usually don't need to. Have pulled over in for a quick potty stop, but usually just use rest areas, McDonalds, whatever for a potty break.
2. We have stopped at rest areas and spent the night. Just kept the trailer hooked up to the truck. If it is hot weather you will want to be able to run the AC so in such cases we just got a campsite for the night, kept the TT hooked up, just plugged in, put the slide out, carried on as normal. We have done long trips of 3 days of driving doing over night campsite stops.
3. Also have used Walmarts for overnights.