I own HGVC but can't answer all your questions since I haven't been to this property.
-Is there any chance of a upgrade to Gold? We are booked into a 2 bdrm with a resort view with a AARP rate.
Highly unlikely. HGVCs operate differently from Hilton hotels and status doesn't get the normal perks.
-Has anyone had any luck with a late check out? The website shows check out as 10:00am.
HGVCs don't give late checkouts, even to owners, since it takes a lot longer to clean a unit.
-Do they provide detergent for the washing machine?
There will be one or two one-load packets/boxes. Usually you can get more from housekeeping.
Wifi is free for everyone, and there are no parking fees.