I love the idea and will be borrowing the slide idea for my own build.... However, I like head room so why couldn't you make your bed move down once the kitchen is out. If the weather is real nasty and you don't want to have the kitchen out you can still sleep with it in it's current location but when you are having nice weather leave the kitchen out and the bed in the down position. Just my $.02.
That is an excellent idea and I got excited for a moment. In considering it, there is one problem with it on my concept. My tires are 12.50" wide and my bed will cover about 50% of each tire to give me a bed that is 1' wider than if I had brought the sides straight up from the inside of the tires (like on Bob's Shuttle Pod). For this reason, dropping the bed down is impossible for it would hit the tires.
Feel free too incorporate the giant slide idea. What I like the best about the concept is the slide is so strong, it re-enforces the frame and is really the only moving part besides the wheels and various hinges.