2 questions re: app.program and iTunes

I've finally finished downloading an entire book in multi-parts so I won't be spending as much time with Limewire. Afterall, I should start listening to the book <g>. My question is -- although I downloaded and saw many uploads while I was connected, do I have to have the application program open when I'm online. Or is just having the shared folder on my desktop (and the "shared" folder - firewall - checked) adequate for sharing.

My other question is that I just finished a very large item (143.9MB - no bit rate noted). It is in my "Limewire" folder and my "saved"folder. But it did not transfer over to iTunes. I can't "import" it, "add" it or drag it into iTunes. This happened once before and I just forgot about it. This file is one I really want. What can I do to get this on to my iPod via iTunes?

Thanks.
iMac OSX 10.2.8

PS. Although I registered, I noticed I'm listed as a guest and my login is denied because of a wrong user ID?????