The HUD is a problem in VR -- that was the main reason I created the Dynamic Cockpit feature. The default behavior for the HUD is a floating plane inside the cockpit and you have to look around to see it all. If you don't like this, you can also make the HUD smaller by pressing Ctrl+Z. This will "Zoom Out" the HUD. The scale of this zoomed-out version is given by the following setting in VRParams.cfg:
3d_window_zoom_out_size = 0.400
If you'd rather have the HUD zoomed out as soon as the game starts, then set the following:
zoomed_out_on_startup = 1
The reticle is independent of the HUD and its scale is controlled by:
reticle_scale = 0.7
You can also change the scale of the reticle in real time by pressing Ctrl+Left/Right Arrows
In my opinion, using the Dynamic Cockpit feature is far better than having the HUD floating like a flat plane inside the cockpit, but not all cockpits are DC-enabled.