Not sure of the complexity of doing it, but making the 29'+ NC's with a bedroom slide out might be an attractive feature. It would provide more space of course and allow a different arrangement of the furnishings.
Why are areas that must be repeatedly accessed screwed down (wood to wood)? This means that eventually the screw holes degrade. Why not put simple latches that can be flipped to open the area. The specific area I am talking about is the area below the stove in front of the water heater which must be accessed for winterizing, etc.
I recommend making your idea a separate thread. I like your idea. I'd like it if Heartland would identify what is behind the panels and in the case of the water supply lines a sticker showing how the valves should be position for operation and winterizing.