A very useful list Created by Outerra forum member Acetone.

 

Outerra includes many debug tools, but they are well hidden for normal user. Some of them may be usefull for moders, others for performance monitoring and a few are just fun.
I have tried to list some of them, feel free to search for other ones  

First, you need to go into your eng.cfg (yourname/outerra/eng.cfg).
Search for the "debug_keys" line and set the value to "true". You can now use the tools listed below :


Various tools

Alt+m and Alt+s : Occulus Rift mode
Ctrl+p : Flight path recorder
Ctrl+F4 : Recorder
Ctrl+F7 : FBX importer
Alt+F5 : Shader editor 
Alt+c : command console (not the same as "p" key)
Alt+F8 : Reload Cubemap (environnemental reflexions)
Alt+F11 : Reduce exposure (not sure why it's usefull)

Bugged/Missing

Alt+e and Alt+s : spawn cubes (not working : they are missing on the public version directory)
Ctrl+k : weird spawn menu

Terrain tools

Alt+t : disable vegetation
Alt+i : display geographic coordinates on ground texture
Alt+n : elevation map. Repeat to toggle between various modes.
Ctrl+n : display terrain grid. Repeat to toggle between various modes.

Debug monitors

Alt+1 : Render tasks stats
Alt+2 : Gpu times
Alt+3 : Textures stats
Alt+4 : Sounds monitor
Alt+5 : Tiles monitor
Alt+6 : Memory tracker
Alt+7 : Models monitor
Ctrl+F12 : Show fps

Secret hidden features 

Alt+v : basic night vision mode (warning : full green screen during day!)
Ctrl+i : basic thermal vision mode

Great post and information. Pinned this topic

By the way, you can access a script editor for vehicle physics by hitting alt+e, after you enter the vehicle