If you are looking for onsite dining, a spa (at least one nearby) and a pool with cabana rental, YC/BC fits the bill. You will have a ton of restaurants within walking distance, could utilize the spa the Dolphin and SAB offers cabana rental only for guests of the YC/BC/BCV resort. The quiet pools at YC/BC are also lovely. Have you considered a studio or one-bedroom at BCV for extra space? If you would rather stay on the resort side, I highly recommend the water view rooms at YC. The YC rooms were recently refurbished and I find YC to have a more "adult" vibe than BC. I would not recommend renting points if there is even a remote chance you will cancel. Copper Creek is lovely, but it's quite remote and you will not have as many dining options as in the EP resort area. We've stayed at the Waldorf and it screams "convention resort" to me. If you are looking for an offsite, upscale resort, I would consider looking into the Four Seasons.
The Riviera is gorgeous, but you are correct regarding the variety of dining choices. You would have the Skyliner to access restaurants on the Boardwalk, however, and you can walk to CBR as well. The Riviera rooms are some of the nicest on property, IMHO. We stayed in a one-bedroom and it was stunning. Second only to the rooms at VGF, IMHO. You can save a little money by booking a standard view room - ask for a high floor in the west wing for a stunning view of Spaceship Earth. If fireworks are back by then - bonus viewing from your room!
It is quite easy to walk between the two properties at the Waldorf. We found the bus service to be horrible and ended up using taxis/ride shares to get to the parks.