I believe the rotation problem you are experiencing is related to the gearvrcontroller not being attached to your camera anchor. From my own tests it must be added to the camera anchor the same way the camera is. Once attached you should set the relative location to 0,0,0 just like you would with your camera.
As far as the trigger not working I used the motion controller R trigger input node and that worked fine for me, as far as unreal is concerned either motion controller trigger should be fine.
Hope that helps