Welcome to the addiction. Ct. is my home, what part are you in? I was one of 6 kids in 7 years. Your family seems like you did it backwards.Usually the family has a few and then no more until years later and Oops. You seem to have done it backwards. I learned a valuable lesson being the middle boy of 5 boys and a youngest sister. That lesson was I'm happy with the one daughter I have, I could never see myself raising 6 kids. Mom and Dad, rest their souls, both passing nth last 6 months, did a good job raising us, Dad used to always say he was successful because he raised 6 kids, none live at home, none are in jail and they don't borrow money. Mom was more generous and Dad didn't know.
Seat belt question is a good one for legality, they don't have them in school buses so are they required in our Skoolies? Of course morally, you want everyone belted. Belts are not hard to acquire and install. I would definitely be looking at a 72 passenger and leaving a couple rows of seats up front would work for your family. Haven't addressed the riding in back while moving issue yet, doesn't concern me yet. I know that you can not ride in the 5th wheel trailer while it it traveling.