Re: A couple of questions
Go on Sportsmobile.com and look at their sections for dinette beds and for "Penthouse beds" to see how these function.
In most states, if the vehicle is tagged as an RV or Mobile Home I believe you are not required to have seatbelts for those in the rear of the vehicle. Of course, being required to have seatbelts and it being a smart thing to do regardless are two different things. My SMB dinette setup, similar to that in the photo, has two lap belts on each side, anchored below the dinette.
The PH bed is usually one or two pieces. When not in use it can hang from the ceiling to provide full stand up height. When in "bed mode" it sits on the siderails at the roof of the van, as shown in those photos.
BTW, that's not a bad price for a clean-looking older SMB. If you installed all that stuff yourself you'd be spending a big chunk of change.