Thanks for the advice.
Yes, it is not good to let the slide shut itself on an empty chamber. That is exactly why most guns have a slide lock, to prevent the slide from slamming shut after the gun is empty. If the slide is locked open, hit the slide release while holding the slide open, then manually (and gently) close the slide.
On the spent casings, you will usually find several brooms around for sweeping them up. I like to keep my lane clean if for no other reason than I don't like to step on them. My range doesn't want them tossed. They prefer you sweep them out into the range. As was said, they recycle the brass, probably to the folks they buy the reloads from. That's why they want you to sweep it out on the range-so nobody can scavenge all the brass.
I've been to a couple of ranges in my area that actually posted signs saying all spent casings belong to the range.
I think that's the only reason some ranges don't allow aluminum cased ammo. They don't want to have to separate them from the brass.