Welcome to the world of owning an older motorhome. Sounds like you need to check the date code on the tires, if they are 7 years old you need to replace them. Being a 454 it's probably a P30 and it will have air bags in the front coil springs for adjustable additional spring weight. Mine have the valves mounted on the front grill with hoses going to the bags. They were blown when I picked mine up. Replacing them along with needed ball joints and all the bushings in the front end and shocks all the way around (6 of them), the having it weighed and adjusting the tire presure accordingly and you'll really be surprised at how well it can ride.
Since your alt belt broke you'll probably need to replace the rubber on the engine, all the belts and hoses, flush the cooling system while you're doing it, if you can do this kind of work yourself you will save yourself a ton of money. I also replaced all the vacuum lines on mine.
As far as the batteries go, the connections all needed to be taken apart, cleaned and reconnected. There are several disconnect solenoids on mine and well, there were a lot of electrical problems on mine that needed to be corrected and you're going to need to take a look at what you have and ask here for specifics.
If you like tinkering with stuff you're gonna love having a motorhome, it brings a never ending supply of stuff to tinker with.
Good luck!