Hello Susan, yes it will fir your 720-0787D.-Nexgrill
I did not purchase this product for a Kitchen Aid grill. My grill is approximately the same size and this cover fits perfectly.
It might be too small by a couple of inches. You need to look for a 62" cover
No. It's made from a waterproof nylon, and I would not recommend machine washing. Anyway, why do it? It's an outdoor grill cover.
Yes. But it might be a hair big. This cover is made for the 60" grill. There is another cover that is 52-56" I believe.