Disable surround sound on audio drivers.
As of update 1.0.438.0, intro videos can now be skipped anytime after the first run of the game.
This should fix your issues with huge FPS drops that come from opening doors or cutscenes.
In Windows 8.1, sometimes the game will appear to start minimized, and any attempts at restoring the game will not work. Disabling Exclusive Fullscreen mode in-game should fix it.
The game crashes while playing cinematics.