I made a mess (500/featured products/Easy Populate)

I think I have a mess on my hands...

A couple weeks ago, I uploaded my inventory using Easy Populate, and was running into some ugly 500 errors that I couldn't figure out. my host was at a loss, too. The odd thing is that, despite the errors, the files seemed to upload and show up properly, so -- as is my lazy way -- I got frustrated trying to figure that out, and just pretended it wasn't happening.

Until yesterday, when I refocused on my inventory. I wanted to start adding featured products, and couldn't do it. I believe there's some corruption somewhere, mostly likely as a result of my 'la la la it's not happening' style. I posted the details here: http://www.zen-cart.com/forum/showthread.php?t=139293

So, what I think I should do is delete the inventory, reinstall EP, and reupload the inventory. Just start the whole process over and try to get it right this time.

Is this a good idea?

If so, how on earth do I do that? How do I clean out the inventory without screwing everything up. I was about to just start deleting everything through the admin, but perhaps that's a dumb idea?

Any ideas?