You need to approach 15 like its a bogey/par at best hole. If you miss the fairway, lay up to the end of the fairway, then try to stick a wedge, always below the hole, should leave no worse then a 2 putt.
Similar with 16, if you dont hit the fairway, play it left fairway on the approach to give yourself a better angle to the pin to save your par, but a 2 putt bogey is not the worst thing in the world.
Good round though, little course management can minimize those snags. Similar to #9 at Oakmont, 15 can be a challenge, but what you can do here different then in real life with a group behind you is go practice those holes from a safe spot, i.e. bunker in front of green on #9. Hit that shot over and over until it becomes clockwork, same with #15 from bunker or rough short left of green, and you should be 1 putting par most of the time.