I want to be able to steer my ship with the mouse, while holding down the right mouse button.

The default mapping uses left+right drag simultaenously, but I want to only use the right button. But when I try to map the "Turn to Face" option to right drag, it doesnt work.

The "ground RPG" keybind set also has a hidden bind for right mouse button that turns your toon with the camera. This makes it easy to use "mouse steering" on the ground while using your keyboard controls to manage directional movement. Anybody know which binding this is?

Does anybody know how to do what I am trying?

edited for clarity

Go to Options/Keybinds - Region Space, go to Camera Turn-To-Face, click on "Left+Right Click" and select "Right Press" from the "Special Keys" drop down menu. Ordinarily Camera Turn-To-Face will automatically turn the ship to the direction of the camera with a single click of both the right and left buttons, Selecting Right Press requires you to hold the right button for the same function, this will allow you to steer your ship with the right button.
The limitation of this is that the bow of your ship will always turn to face the camera direction
when the right button is held so you can only use the left button to look around.

Note: Right Press doesn't interfere with Right Click functions, just don't hold the button down or you will turn the ship.

Selecting Right click in the options will cause the loss of right click functionality on the UI and it will also cause both the left and right buttons to steer the ship, which is not a desirable outcome
Right Drag won't work because drag is telling the game to read Mouse motion, which isn't needed for this key function. Left and Right drag are already preset to turning the camera, re-assigning right drag removes if from the camera option essentially disabling camera turn with that button.
Hopefully this helps, experiment with this and see if it works to your satisfaction, good luck and have fun.