You may want to untether look direct from walk/move direction in the Oculus Rift. In other words, if I decide to gaze towards some mountains to my left while moving forwards, it shouldn't make me suddenly walk/move in that direction.
Your cursor and move direction should be tied to the mouse(/gamepad) and a freelook should be the direction your head is facing, imo.
Most of the best rift experiences do it this way for immersion, and I think space engine would benefit from it as well.
That might be something you can assign in the F8 menu - I don't have a Rift, so I cannot check, but there is a middle-mouse-button free-look mode you might be able to re-assign.