Man this all seems like way too much work to get the game to be full screen WITHOUT any issues. I'll deal with the black boarders they don't bother me that much :-) That is, until a legit patch or fix comes out that makes the game full screen without issues.

Indeed, Sgt_Breakdown.
Editing files, disabling write permissions, attempting to start with "oc1.exe game", creating custom resolutions - nothing works here. It's kind of a drag that you're forced to use an unstable 3rd party loader if you want to actually see game, as opposed to staring at a tiny box in the middle of the screen.
Well, at least you don't have to slow down your CPU with the GoG release, but still, it's not something I'd call compatible with modern PC's :-)
</rant>
(Sorry.)

Have you guys not seen the fan patch in the other thread..? It takes care of everything and works mostly great.
http://www.gog.com/en/forum/outcast/final_640x480_fullscreen_patch_stable_some_aesthetics_problems_fixed