R.E. the trailer, given the current state of recreational stock due to COVID, I'd check if your local RONA has any new trailers in stock. If not, you may be able to get back what you paid for it, lol. Gotta be some fool out there who bought some dirtbikes over the winter and now needs a trailer.
Yes, the tonneau has to come off. It should be fairly easy, a couple of twist knobs, no tools required. I take mine off all the time when I need to haul large objects, although it's a little easier because the soft tonneaus weigh less than the hard ones.