The most important thing you have to adjust is the field of view (FOV), which has to be higher than for playing on a monitor in full VR mode (120° for Vive).
For some games the Optimizer does that, for others you have to do it in the game’s option menu, the vorpX ingame menu (Skyrim for example has an “Adjust FOV” button in the vorpX menu). If none of these is available an external tool like Flawless Widescreen or Widescreen Fixer might help.
If you didn’t do so already, please read the Essential Hints guide in the vorpX help, which explains this and other noteworthy things. The help also contains a quick and dirty setup “1-2-3 Game Setup” that always works, but doesn’t provide the best possible result.
If games open in Virtual Cinema Mode there usually is a reason for that. Third person games for example ar better played that way. First person games however open in Full VR mode per default. You can disable Virtual Cinema Mode in the vorpX ingame menu (press DEL), but for third person games it’s usually the better choice.
Ark and SC2 are not supported games, they might or might not work.