Did you do step 18 before you wrote that list ? I think a couple of things are slightly out of order.

Steps 1-4 - I guess you're putting up the straight sides, my recommendation is to:
1. Level entire site using transum or water level
2. Lay out where patio blocks for side structures will be, lay those level with ground (dig holes, I guess)
3. Build side structure as instructed.
4. Use water level or transum to check for level.
5. Place sand, wall, liner, some planks inside pool
6. Set bottom track - I wouldn't bother with Patio blocks since anything non braced carries absolutely no weight - you can do whatever you want though.
7. Unroll wall using planks to stand and move it on, install uprights.
8. Level sand
9. Install coves
10. Install liner - however it needs to be installed - 3 types, 3 ways.
11. Hook up shopvac to skimmer hole with a cardboard cover also tape off return hole.
12. Get liner set so it hangs perfectly straight up/down, no skew, make sure wall/floor seam sits at right spot all the way around.
13. With Vac on start filling. - turn vac off once you're at 1' or so.
14. While filling, install top rail/seat/cover - whatever you want to call it.
15. Once water is a few inches from return and skimmer, cut those in (make about 1/16th smaller than metal cutout).
16. Hook up skimmer/return and plumbing