BWV,
I'll take a stab at your questions.
I think a 32' rv will fit on the Premium sites with a car. Premiums are usually over 50' long and very wide (18' paved) so it will work.
Preferred sites are the CLOSEST sites to the boat landing (loops 100 and 200). One side of the dock is the express run (the big boat) to MK and back. The other side is the shuttle boat (think like Jungle Cruise boat size) which runs between the Contemporary, Wilderness Lodge, and the Fort. I think the proximity to the beach for the fireworks, EWP, boats, etc are a huge plus for Preferred loops. Premiums 400 and 700 are next closest to this area.
Preferreds are only 12' wide paved and have the sand pad (Premiums paved over the pads when they were created out of the existing inventory). You might be able to put the back wheels of the RV on the sand pad with some support for the jacks but an rv person would know more about that (which I am not).
Golf carts are a sore topic here. Disney rents them at the Fort (expensive) and off-site vendors can provide them (inexpensive) but Disney recently made it very difficult to use the off-site vendors. They say it's for reasons of safety (too many golf carts at the Fort at peak times) but I don't believe it one iota. The number of personal golf carts WAY outnumber the rental golf carts from outside vendors.
Disney's rate is $59 per day flat rate plus tax for your typical 4-seater. Off-site vendors are about $40 per day or less with discounts for multi-day. But what Disney has done is prevent the off-site vendors from delivering the golf cart to the Fort for you and picking it up at the Fort. You must meet the vendor off the Fort property to come in with the cart or haul it yourself on a trailer (if you have a hitch). For a Disney cart call 407-824-2742 to reserve a cart up to a year in advance. They will take a credit card number but not charge it in full until the day before you arrive. As an off-site vendor people frequently use Tee Time Golf Carts at 407-276-0809 and leave a message if needed. Make sure you understand the arrangements both getting it and giving it back (they are good folks and pretty flexible). Off-site vendors don't have unlimited inventory so when depends on when you are travelling of course-they do sell out at popular times. Whenever you know your plans, give Tee Time a call. Again, Disney is deliberately trying to make their lives difficult.
Come back at us with follow-up questions. I hope folks with rv's or long trailers will chime in about the different types of sites.
Bama Ed