Is it okay to just throw it out with the trash? Or are there special steps to follow, like the disposal of medical syringes? Sorry if you think the category is off - the choices weren't very applicable to my question.
The holes *have* to be drilled right on the money. There are jigs for this. Other than that, the lock has to be, well, straight. If the outside is a little high and the inside is a little low (same with left/right) it will make the lock hard to turn. Loosen the screws that hold the lock on, and look down at the little tongue that runs between the cylinder thumbscrew. That should be level front to back and square to the lock left to right. If it's off a little, the lock will be hard to turn. If it's off a lot, the lock won't work at all.
Yes, as long as there isn't any mud or other stuff on the bb. I wouldn't try to clean them.
fuses are relatively cheap.. a few bucks which ones you need? read your owners manual or when you go to Auto Parts Place to replace them, ask them to look the parts up for you
Make sure they are still round and not damaged. If they are damaged or have debris on them, you will scratch the internals of the air gun, and they will not shoot straight. An idea is to have a sort of BB catcher. Have a sheet or blanket hanging up somewhere, and make it so when you shoot at it, the BB's roll down the sheet and go to some kind of container like a bucket or box. Then just get the BB's out of the container, clean them, and shoot them again.