I think that any of the above might be correct... but which one?
I would leave the camper on the truck... ask my alignment mechanic to do a test drive. Then I'd take the camper of the truck... at his shop or drop it off at home. Thene I'd trust the alignment guys to do whatever is necessary... it will be well within their skill and abilities.
I'm fortunate:
I know my alignment shop and the people that work there ( Troy or John at A1 Alignment in Oak Ridge). I have them do all of my vehicles... an alignment from them is about $50.00 )
When they get through... the front end tracks true, the steering wheel is oriented correctly, and the tires will wear evenly.
In the end your alignment shop will prevent you from making unnecessay repairs and missing something that could cause a real problem sometime when you least expect it... The guy that sold it may have had the problem... and didn't know what to do.
Good luck... I'll be watching for your solution.
Sleepy