Well, #2 is now "known". Paragon Gaming will take over casino operations.

From:

http://vitalvegas.com/mirage-las-vegas-resort-will-be-sold-to-former-owners-of-riviera/

"Once the sale of The Mirage is complete, the casino will be managed by Paragon Gaming, the company which took over operations of Westgate Las Vegas after the sale and closure of the Riviera.

Paragon Gaming managed Riviera’s casino for two years prior to the Riviera closing on May 4, 2015."