Please see the most recent updates in the "Where did the .com name go?" thread. Posts number 16 and 17.
Please see this thread for updates. Update Thread
SOH ADMINISTRATIONI don't know of anything in either of those files that would control the max visibility distance of effects. Like the clouds, I believe that's hard coded into the game engine. The clouds go out about 8-10 miles, and that seems to be where the effects visibility gets cut off.