It's not visible at all, so you would not probably see it.
It's by the bathrooms that are to the left of and kind of behind the counter area. You need a CM to take you there because it is totally backstage.
Coming down is just as challenging - you have to find a CM again to let you backstage to leave.
I have a feeling that the Fire Marshall probably was not pleased with that. In case of fire, there was no way out for guests who could not go down the stairs.
My guess is that was one of the reasons they made the area downstairs - since half of the seating is not accessible, it makes sense to designate some of it for use by people who are only able to use the bottom floor.
Yes.
I think the CM was being very literal about the sign having a picture of a wheelchair on it (and maybe not realizing that meant handicapped, not just wheelchair).