Ok as for “they appear somewhere else with every compile” the answer has already been given: when radiant safes the map it stores it differently every time. So don’t worry about it, you can’t change in anyways.
For the compiletime: u could save a lot of time by getting rid of bounce 8… bounce 2 is sufficient. Iirc a high bounce sometimes can produce weird coloring/shadow-effects too, but i forgot where i read about that.
To get rid of real dark corners etc. I recommend a low ambient (around 10-12). Yea yea i can already hear the flaming “flattens maps out” and “Ydnar said it sux”. Anyways its worth a try and an ambient of 12 gives you a more even lighting, not a flat map. You ll only notice it in the areas that were pitch black before. Next advantage of a bit of ambient is that it gets u rid of the problem that you have to illuminate EVERYTHING with light entities.
Its a real pain in the ass when u try to illuminate everything with lights, and if you use a lot of them with different fades and maybe some with a light 30 and fade 0.1 to give everything a base lighting you ll still end up with unexplainable shadows. So from my experience with getting decent lighting a low ambient is a good thing to start with, and then add the light/shadow-effects you want with light entities.
As for sky and sunlight: which shader are you using? I m sure a new custom skyshader could improve things a lot, esp. with a sunExt instead of sun parameter. And: do u use that shader in the town-areas too or only for the terrain-boxes?
Edit: a nice example of “flattens map out” is et_ice, i think it has an ambient of around 25. I quite like the “white-out” effect for the terrain though because that s really pretty much what you get with a thin layer of low clouds on winter days: barely any shadows. Its just a pity that all the caves and tunnels are overbright too.
).