While I do have on-ice officiating experience at the amateur level, it would be quite the jump for me to suddenly take on the job of NHL officiating director (which I think is what you're hinting at). NHL rules also differ in several areas when compared to USA Hockey rules. For the sake of my own curiosity, I'll run through some of the major differences.
-Checking from behind is generally permitted in the NHL. While there's a rule to cover it in the NHL rules, it only covers hitting a player from behind who's defenseless or unable to protect himself. It must also be called as a major plus game misconduct (or match penalty), and in practice I've legitimately never seen it called. Also in practice, a player who hits an opponent from behind is often guilty of something else (such as boarding), so they'll call that instead.
-Faceoff locations differ quite a bit. While I stopped officiating USA Hockey after the 15-16 season and they may have changed it, faceoffs can occur anywhere on an imaginary line running between the two end zone faceoff dots (and through the neutral zone faceoff dots). The center ice faceoff dot is only used to start periods or after goals. While I won't get into the nuances of how they differ, I will mention a major one, which is that the faceoff location to begin a power play is a "last play" faceoff, with the exception that a team on a power play cannot begin a power play in their own zone, so the faceoff is brough out to the neutral zone instead. In the NHL, power plays begin with an attacking zone faceoff (with a few exceptions).
-USA Hockey prescribes "automatic" icing rather than hybrid icing. There is an addendum to cover hybrid icing, which can be optionally used, but the rules state that automatic icing is preferred.
-Rules on kicking the puck are much less permissive in USA Hockey when it comes to goals (kicking the puck is otherwise legal in all zones). There is no "distinct kicking motion" rule and redirects off the skate or leg result in the goal being disallowed unless it was clearly an incidental deflection. There are a lot of times I see something called as a good goal in the NHL (and correctly so) that would be illegal in USA Hockey rules.
-Attacking players in the crease are restricted heavily in USA Hockey, and so are rules about interfering with the goaltender. The NHL allows incidental contact, whereas USA Hockey does not. The USA Hockey rules are essentially the same as how it used to be in the NHL, stating that an attacking player may not precede the puck into the crease for any reason. You can even blow a play dead for a "crease violation" which will bring the faceoff out to the neutral zone, but in practice, if a player quickly passes through the crease (unless the puck is quickly put into the net afterwards, in which case the goal is disallowed) it gets let go, and if an attacking player is in the crease you yell at him to get out and give him a chance to do so, only calling the crease violation if he refuses to leave.
-The standard of enforcement in USA Hockey is generally stricter. It's similar to how you would see things called in IIHF tournaments. Lots of things that would be uncalled in the NHL are generally called in a USA Hockey game. There are sometimes things in the NHL that get let go and I think to myself "wow, that would be worth 5 and a game in USA Hockey rules." One of the bigger examples is that if you injure an opponent with a penalty, it's automatically 5 and a game. This includes high sticks that draw blood (which are a double minor in the NHL), although you don't really have to call it much since most players are wearing full facemasks (I did have to call it once though). On a side note, unless they've changed it recently, adult players are permitted to not even wear a visor if they so (stupidly) choose.
-Game misconducts result in an automatic suspension for a number of games equal to how many game misconducts you've received that season. I think there's a rule where if you get a third one, you get suspended indefinitely pending a disciplinary hearing, but I'm not sure about that one. Also, match penalties are automatically an indefinite suspension pending a disciplinary hearing.
There are more, but I think I'll stop here before I get carried away.