The Taylor instructions say to use two scoops and somewhere else on this forum (if I remember correctly) somebody experimented with differing numbers of scoops and some people got slightly different results. With my own testing, I found that it didn't seem to matter at the chlorine levels I was testing, but as a general rule I think it best to follow Taylor's instructions as can be seen at this link for the K-2006 kit.

Your higher TA is perfectly fine since you've got a vinyl pool so can have lower CH (which you have). The only issue with higher TA in your situation is a tendency for the pH to rise, but you don't see that because you keep your pool covered (with a solar cover) and probably don't have aeration features (fountains, waterfalls, etc.). If you had an SWG, then the higher TA would likely cause a very large rise in pH.

Richard