It was 31$ for valet parking and 28$ if parked next door. We checked in 6th of October and checked out on th 7th.

Yes

No, there isn't. Take uber, it's a $20 fare only!

Don't know the answer to that... You should give the hotel a call

I have seen ajoining doors there before.

Paid parking

No

As far as I know yes; make sure you mention the conference too get the proper rate.

I would not know you would have to call and ask them

21 alone