I'm a little unsure if I'm posting this in the right place...
How can you make a weapon usable (visable, selectable) in one level, and unusable(invisible, unselectable) in the next?
Over 3 years (has it been that long?) and just now I noticed the day and month of my birthday were switched. Whoops!
When the level changes, simply take the weapon away from the player. There are several ways you could do this. I prefer using a script where I can use the SetAttribute command to take the weapon attribute away from the player.ini file. I am pretty sure you could do this with an entity, but I don't have much experience with entities, since I usually just replace them with scripts.