are there wheelchairs available to assist people to their seats

I believe yes

Is there places to stow walkers..if so where located

Yes

Yes, best to call them up in advance

Yes. Call guest services. But be prepared. There are alot of requests. Depending on seats you should have elevator access as well.

Yes if you arrange it with guest services, they also have seating available for guests with special needs

I haven't seen any, but I would call guest services.