The bolts that hold the AC to the roof should not be tight. If you tighten them too much they will compress the foam seal too much and could develop a leak that way as well. Check your manual for a tightening spec or google it.....
Congrats on the new trailer and I certainly relate with the cabinetry being below par.
2014 Jayco Swift 281BHS
2015 F250 XLT 4x4 Crew Cab, Short box, 6.2 gas
Solar powered! The trailer not the truck!