At 800x600 resolution, I'm getting some overlapping text, namely in long save file names (particularly those stemming from old maps), and on the custom game mode screen, where "Player-Vehicles / Bots" drops down a line and intersects "Physics Vehicles."
Setting the sun flare really high makes for a pretty sudden jump in effect when it leaves your field of view.
I raised the fog and visible distance all the way up, dropped the visible distance all the way down, then raised it back up again, and the fog appeared to have returned until I adjusted it a bit.
My torso appears able to be lit by the sun, while my head does not, creating this strange effect:
Both my head and torso are pitch black.
The sun flare can be seen through bricks when pressed up against them. Most noticeable when the sun is at a low elevation, or through a ceiling brick when it's directly overhead.