I'll take a stab at this.
Take your trash with you to the dumpsters in Trellis Bay - free.
Scrub has a discount off season, but not sure when that is. Be sure to include their resort fee.
Ferry is free in both directions, hourly.
I believe the outdoor restaurant, Tierra, at Scrub has finally re-opened. Get a reservation for the outer tables (by the water) unless it's raining. Much better than the indoor restaurant, IMO. Or go to Marina Cay.
Not a boater, but the cats go in backwards, as I recall. Can't recall about the monos.
Grocery is highly variable, depending on season. Good for beverages and shelf-stable stuff; very limited on perishables. Not cheap. Better selection and prices at Trellis Bay Market, or taxi to the East End Riteway.
We took a friend with Celiac to Hog Heaven. The owner was extremely knowledgeable and much of their menu is gluten free.