Inventory manipulation

I always clear cache before logging off because it seems to reduce so many problems, so each time I log on, my entire inventory "refetches". From time to time I notice that up to 800 items don't seem to make it, which doesn't worry me that much since a few log-ins later they turn up again.

However, if I move a folder which has a few hundred items inside of it do the missing items get moved along with it? Or is that the way of making sure they'll never turn up again?

What if a folder looks empty, but there are supposed to be things there that I just don't remember, and I delete it? Does the folder reappear when the items get restored, or is it just all gone?

I'm long overdue for some inventory cleaning, but with the constant varying amount of items I seem to have I'm just too scared to move or delete any folders that appear to be empty .