1. You can rebind all keyboard shortcuts in the config app (‘In-Game Key Bindings’).
2. Two answers, depending on what you mean with your question: if you don’t want vorpX to engage entirely, you can either pause/exit vorpX from its tray icon’s right click menu or alternatively exclude the game in the config app (‘Excluded Programs’). If you want to play in 2D in your headset, you can disable 3D in vorpX ingame menu.
BTW: If you haven’t done so already, check the quick start guide and the essential hints guide in the vorpX help. Many basic questions are answered there.