ResolutionSizeX=800 //put your desired resolution here
ResolutionSizeY=600 //put your desired resolution here
WindowPosX=-1 //I dunno
WindowPosY=-1 //I dunno
bUseDesktopResolutionForFullscreen=False //probably what it says
FullscreenMode=2 //set to 1 if you want fullscreen
Put that in Perf/Saved/Config/WindowsNoEditor/GameUserSettings.ini
for custom resolution-ing
One neat thing I discovered while testing this was that Unreal's resolution up-scaling is very nice.
I'll look into the keyboard stuff.