We've only stayed at SSR twice, but here was the information we gathered.
Quick Service: Artist Palette is one of the best QS in the DVC system. Definitely worthwhile for a quick bite to eat.
Table Service: Turf Club has gotten many thumbs up over the years, but some recent definitive "thumbs down" reviews. We've never eaten there but with so many choices within walking distance at DS, I would probably head in that direction for the variety and quality offered.
I'm not sure what qualifies as a "must do" at any resort. It's so personal...some people might find strolling around the grounds a "must do" while others feel it's a "must avoid". We enjoyed our time at SSR but didn't partake of the spa. One other thing you can do is to tour the current DVC resort models at the DVC Center there. Aside from that, I'm not sure what kind of hidden gems are at SSR. Enjoy your trip planning!