That's a good point, yeah, you're right, the most selfish thing would have been to let everyone get shot, but on the other hand, even that wouldn't have guaranteed that Moriarty would leave Sherlock alone. This way (faking suicide), Sherlock guaranteed that Moriarty would leave Sherlock alone (as well as John, etc.). Or rather his minions would, given that Moriarty himself was dead by then. (And I do believe he is well and truly dead.) I guess I think that Sherlock is the one who needs to take the first step in this case. I also think that John does understand that Sherlock's actions in Reichenbach were out of some twisted sense of noble sacrifice, but that doesn't change the fact of his betrayal and massive lies. I am sooooo anxious about how everything turns out in the next series! They could take it so many different ways, but one thing's for sure, it will be angst-o-rama!