I'm a much better carpenter than a mechanic ... and I'm only a mediocre carpenter. So this has all been a learning process. But I built my house (fondly known as "the house that incompetence built"), so this should be a breeze ... right?
Went with laminate vinyl faux hardwood flooring for the interior. It was pretty pricey, but I saw too many photos on this forum and of old RVs with moldy/disintegrating ply subfloors or laminate wood flooring. With young kids I count on a high spill factor. While mold seems able to grow about anywhere, at least the floor/underlayment won't absorb moisture and disintegrate. So the price seemed worth it, especially since I only had 100 sq ft to cover.
After three months nonstop on the road, it held up pretty well to a family of five. There was one spot where the "snap-lock" planks started to spread out end to end. Not the prettiest, but not that noticable. Plus it's the "distressed floor" look, so it shouldn't be perfect anyways, right?
I heard a lot of pros and cons both ways, but I personally decided not to glue down the flooring because I wanted the floating floor to account for expansion/contraction of materials. But that left them a little loosey goosey on some of those bumpy back roads - that may be how that gap opened up.)
The oh-so-common slide out couch/beds worked amazingly well in a shortie where space is at a premium. Each side could fit three passengers with seatbelts, and when the bed was unfolded it slept four comfortably. The seat/back mattress rests became the bedding. We used 4" foam from HD and then my wife found some pretty amazing fabric. Then about 8 cans of scothch guard because, like I said, young kids... (and if I'm being totally honest I might sometimes spill some beer. Never my first, but sometimes my fourth
Pros on that bedding style/system is that it's very space efficient and you have good storage underneath. And it also covered up the wheel wells. The biggest con was set-up/take-down on a daily basis. Very easy and quick with two people, a little longer if doing it solo but totally doable. One thing I feel helped me was a fair bit of routing on the slats etc. The slide "sticking" was never really an issue. However, the seatbelts were a bit annoying because they would slip between slats and have to be fished out when you were converting from bed to seats.