Fog of view is is simply the fog effect to make the clip plane less dramatic. Personally, I like to have fog off and have my clip plane visible as it gives me better visibility, though that is simply my preference. And yes, I agree, the clip plane should be adjustable (on the fly even, hotkeys are good).
Level of detail is the amount of detail put into objects. This can be adjusted depending on the game. In recent games (UT2k4 for example) you can set the level of detail for different objects (walls, floors, players, etc.). In other games it simply does it based on distance. Depending on how far away something is, less detail will be put into drawing it, which actually won\'t change much since it is so far away. This is how PS probably will work.