Ratings

Does anyone know how chess.com ratings compare to USCF? 

So for example,  my standard rating on here is about 1550. Would by USCF rating be anywhere close to that?

It depends. There are a lot of posts on the forums about chess.com and USCF rating correlations. I don't have many Live standard games played here but it is closest to my OTB rating, within 100 points right now (80 but who is counting ). Actually my Quick Rating is also pretty close.

So, you might be +/- 100 but you could even be more than that. Just depends.

The only real way to tell is by playing in OTB tourneys. Until you have done it, there isn't really a way to tell and OTB is a lot different than online.

Does chess.com identify what openings you played after every match like lichess?

There are some problems:

1. Some player are as good or better with a 2D board on screen, some are much worse then on a real board.
2. The time controls are different. Here you play something like 15+0 or 15+10, USCF standard games are much longer
3. The players pools, mean reatings and the rating distribution are different.