The second screenshot is across open land where there are no roads buildings etc.
Ah, well, the texture shows several farm roads and outside of OSM2City, FG does not try to depict every single building there is in reality, so what exactly do you mean by 'there are no roads, buildings'? In reality, or which you see on screen? Do you expect that there needs to be a 3d object creating a light whenever you see one?
Obviously I accept the risk re fuel but at the moment I just fly small aircraft. I can always delete the code if issues occur.
It's obvious that you can do that easily - the harder problem is to spot when you should. The usual chain of events is
1) hey, great option, I never need to worry about fuel in FG
2) changes into a heavier jet and crashes a few landings
3) writes angry forum post 'this jet is impossible to land'
4) nobody can reproduce the problems
5) general annoyance
(I'm not sure why you feel you need it for small aircraft - single prop planes go quite a while with a normal fuel load...)
What is a 'fogging error'.
An (rgba) value mixed with the base surface color that's inconsistent with the rest of the scene. Feel much wiser now?