Simple solid chess will get you to 2000 USCF
I am convinced that you can get to 2000 USCF without really knowing all that much about specific openings and endgames if your chess is tactically sound (i.e., you see almost all 1-2 move tactical threats and oppotunities) and you have some basic positional knowledge. Take the following game. I did not know the opening, but muddled through it at least as well as my opponent and them simply capitalized on a succession of his mistakes. Of course I am currently only rated in the 1800s, but if you play this way you should not lose to hardly anyone below 1800 (because most have major tactical or positional holes in their chess).