Tried everything - pressure washing, deck cleaner, stripping to get the old stain off this possibly 30 year old deck and short of tearing it down (oh if I only had the cash for a new one) we decided to sand off the old, peeling, cracking, splitting stain. We rented a square floor buffer and a vibrating hand sander. Started with 80 grit on the floor boards (which did absolutely nothing) and now we're down to 20 and 36 grit (the only grits that taking the stain off and not all of it). We're going back over it with 80 to smooth it out. The 80 grit worked on the railings, but not the stairs. The deck seems to be pressure treated pine (we just bought the house from someone who had let it go to pot) and seems to be primed and stained with Cabot's Cape Cod Gray.

Here are my questions:

The stain came if in some but not all places. If it came off whole, I would have used an oil based transparent or semi-transparent stain, but it didn't, so what do I use on this spotty mess? Assuming a solid stain, can I use an oil based primer? If I due, do I need to use an oil based solid stain or can I use acrylic/latex stain? Do I have to prime?

Do I need to wash the deck after we sand or can we get right to priming/staining. We've been using a leaf blower for the dust as we go along.

Is there an issue if I leave it in its sanded state for 2 weeks before I am able to prime or stain?

Should I forget the staining idea and go right to rustoleum's RESTORE?