1) if you're having frame issues at higher resolutions then the videocard is probably running out of ram (textures aren't optimized yet).
No, I'm not having frame rate issues. The fps is resting at a perfectly acceptable 30-ish. The problem is that this fluctuation in the frame rate appears to be causing a very subtle change in the timing of the game.
2) You can 'buffer' your next move with the keyboard. Example: hold down the left arrow key to go left. After you start moving then hold down the up arrow key. Because the up arrow was pressed most recently it will take priority when you reach a 'crossroad'. In your case by buffering the 'up' key the player will go into hiding as soon as is possible. This is a great way to cut corners and get from place to place as quickly as possible!
I know---I'm already doing that. With the change of timing, I believe that this level becomes technically impossible to solve because something is timing out differently than when the level was designed.