Menus that are outside your view are best used in EdgePeek mode (press the mousewheel), which temporarily switches to a cinema like view.
Enhancing the FOV is crucial for full VR mode. What can be done in this regard varies from game to game. In many games this is solvable perfectly, in others you may have to live with compromises. The Essential Hints Guide in the vorpX help lists the various options vorpX provides to deal with the matter.
For Far Cry 3 please make sure to disable the Uplay ingame overlay in the Uplay options. Some Ubisoft games don’t hook with it enabled unfortunately. Also try both the DX9 and DX11 version of the game. One might work better for you.
Arma III requires BattleEye to be disabled. Since a BattleEye update some time ago vorpX does not work anymore with it.