If you book two rooms do all of get the benefits of "Diamond status"?
From FT:
can address only my own experiences:
1) I was told that if a hotel had the suite availability, I could use multiple upgrades at the same time. They did, and I did...but only 2, not 3. i did this twice - once at a Park Hyatt and once at a standard Hyatt.
2) Neither of the above hotels had a lounge, so that did not apply. I did sign breakfast to my room, without issue. But it should be noted it was 4 adults with a reasonable breakfast bill. (not directed at OP, just sayin'....)
When I have booked rooms (never more than 3), they remained in my name, and I was paid the bill, I have never been denied Diamond benefits for all rooms.
All my stays are US, and have never occurred at a major resort in peak season...so YMMV.