I'm not a single but we've befriended singles in the past. No need to just stick with other solo travelers. Trivia, excursions and shared tables are good for facilitating mingling. Many couples are not joined at the hip.
That's disappointing, don't remember this in the past. As for CR, there's no excuse for bad acoustic architecture--this should be integral to the design from the get-go.
I found the specialty restaurants on Riviera all overdone and rather ersatz. And the MDR quite lacking compared to Regent. Then again, La Reserve was exquisite.