You mean the part in the AI Wander Package that says "Distance"? http://img146.imageshack.us/img146/9717/87291417.jpg
If I have that set to 0, then the NPC will be frozen?
Not frozen, he will play various animation idles. But if you want the NPC to move, you have to set a distance in units, yes, and do not use idles 100% of the time
Game units are ... how lengths are usually measured in game, similar to pixels for images. Also TESCS uses them to measure lengths.
I mean what is 4 feet in the game? What units of measurement are they using for measuring NPC distance?
a NPC is about 128 game units
a cell is 8192x8192 units
details from MSFD dedicated paragraph (it is useful for a modder to slowly assimilate MSFD)
1 game unit = 0.56 inches
50 =28 inches
500 = 23.3 feet
5000 = 233.3 feet
8192 = 385 feet = 1 game cell
1 game unit = 1.42 cm
100 game units = 142 cm = 1.42 meters
1000 game units = 14.2 meters
8192 game units = 116.33 meters = 1 exterior cell
The island of Morrowind itself is 5.00 km north to south and 4.65 km east to west.
To optimize rendering, the engine processes AI, and animations in 7192 units max. radius centered on the player.
It does not matter if you give an AI command using scripting or the NPC AI form, this is the working limit. You can force it higher using MW FPS optimizer, but you will have animation errors, so MGE correctly caps it at 7192 like the game engine does.
Note that you can use a AI command with a 10000 radius unit, or give a AITravel command to cell 50,50, the AI will (slowly) calculate the route, but the creature/npc movement/animation will always freeze in the middle of the trip when player is more than 7192 units away.
I don't know if freezed AI packages when player is away can survive the 72 hours standard garbage collection, I have only used long-range distance AI packages with creatures deleted as soon as player was distant, but I suspect there may be problems because mods with caravaner NPCs are very tricky to make.