Ctrl+O doesn't bring up the options window, it brings up the list of tribe members
But we can't find where to setup or where the existing keybinds are for selecting a tribemate

Pressing Ctrl+O again hides the list of tribemates.

Edit - Solution
After talking with author, discovered that Right Ctrl doesn't work, that it's Left Ctrl + O for options, also
Default Keybinds as per author:
[3:22 PM]
[GIRLZ]_Lajumelle:
So by default, the keys are :
(L)CTRL + O : Toggle option panel ;
O : Toggle tribe panel ;
P : Switch to next player.