search distance? what?
as long as there are pathnodes, zombies will find you, so there's an error in your pathings. if you've ever played nazi_zombie_lighthouse, they came from MILES away.
to make a custom weapon work (gg cfg) as a buyable weapon you need to add it in zombiemode_weapons and make a price for it, then add this line from zombiemode_weapons into zombie.str.
you'll need to add the weapon into dlc3_code.gsc if you want it in the mystery box.
(https://www.ugx-mods.com/forum/proxy.php?request=http%3A%2F%2Fi47.tinypic.com%2F27y1owp.jpg&hash=093946e81b302b51dafbcdbbdf366ef5ec14e447)
copy the line in the middle over to zombie.str
(https://www.ugx-mods.com/forum/proxy.php?request=http%3A%2F%2Fi47.tinypic.com%2F166gkef.jpg&hash=e7ad9b9adb632789a6cfeaa99516461c600b842e)
hope this makes it more clear