Is this place wheelchair accessible?

Yes

Yes, it is wheelchair accessible, and they have motorized wheelchairs too.

Absolutely! I actually think a motorized wheelchair is probably the best way of getting around!! They do have golf cart typr cars but I believe those have to be specially reserved before showing up.

Yes most sites, except maybe the treehouse i remember to have wheel chair access. As other members said, the grounds themselves are mostly flat

It's pretty flat so I would say yes

Most of it is as far as i remember. There's also a few shuttle/carts that drive people with mobility concerns around but i think you need to call ahead and schedule them.