Dagger Shortcut: Only thing I can think of for the dagger early would be the poistioning. I tend to poistion myself so when I run up the wall I am pushed slightly by the slope on the block above you, then I jump across to the other wall and bounce back. That tends to get me up there more consistently.
Breaking the wall to the mess hall: Probably position yourself a distance away from the section of wall you break, kill 2 enemies, freeze one and hopefully Farah is dealing with the other. If not you'll have to freeze him too. Then as they are frozen move towards the wall and break it. If you have frozen them a decent distance away, by the time you get to the wall the auto lock onto the enemy should be broken and you should be able to face the wall and break it down.
Breaking the wall to the mess hall: Probably position yourself a distance away from the section of wall you break, kill 2 enemies, freeze one and hopefully Farah is dealing with the other. If not you'll have to freeze him too. Then as they are frozen move towards the wall and break it. If you have frozen them a decent distance away, by the time you get to the wall the auto lock onto the enemy should be broken and you should be able to face the wall and break it down.