Intel Mac :: Alarming Number Of Files In Trash?

My computer has been acting strangely so I decided to empty the trash since I hadn't done so in a couple of months.  The finder shows 110 "items" in the trash- some of them are folders (some of them iMovie temporary items), so I realize I have more than just 110 to delete.  I don't  trash many things, and certainly don't use the trash for storage!  I was quite surprised and alarmed when the status bar showed over 16,000 items being deleted, so I immediately stopped the process.  I then saw the trash included user files (copies?), dated the exact time I started to empty.  This, together with the fact that my computer has been flaky at startup, and quite un-mac-like in frequent freezing and other troublesome behavior, had me quite concerned. 

I asked a similar question over the weekend, but obviously wrote it too quickly and didn't make myself clear, as I only received snarky, unhelpful responses. I would really like some advice here, so I am trying again. 

I do use Time Machine for backup, I'm hopeful that is the reason for the large number of files (including user files) in my trash, and that it is safe to go ahead and empty the trash.  I'd guess that many unnecessary files would be contributing to my initial problems.  However, I would feel much better if I had some confirmation from this community.  If this is the case, I am also curious if I can change something so that I don't continue to have this many files going into the trash. 

Info:
iMac, Mac OS X (10.6.8)