We have a 2012 Heartland Bighorn and we have had a few problems most I was able to resolve myself, including a slide that wouldn't go in or out. Nut which secures the hydraulic valve fell off. The list of problems that you have had are average in the industry. Refer and AC problems were caused by a different manufacturer, the one who made the appliance. Driving them down the road will shake things loose so you will be repairing more things which is the nature of the beast. It sounds like your dealer is making an honest attempt at resolving the problems.
Soon the outstanding issues will be resolved and you will be able to enjoy your new FW.
2012 Heartland Bighorn 3070RL, Trailer Saver BD3
2015 GMC Sierra 3500 SLE CC, Shortbed D/A