It sucks to hear that you are having all these problems with something you should be enjoying.
I understand that all trailers have their issues but posts like this are exactly why I am hesitant to buy a new trailer. The one I have has had minor issues but nothing I couldn't either fix myself or wait to take to the dealer (it's only been in twice in the 17 months I've owned it).
I did recently have a slide issue but it seems to have fixed itself because I checked it this past weekend and it worked fine.
What other industry would it be acceptable where a consumer would hesitate to make an upgrade purchase for fear they may be one of the unlucky ones to take ownership of the "Friday build".