Try this:

1. right-click on LW in the system tray
2. select 'exit after transfers'

I believe LW will not initiate any new uploads this way, but will allow your current uploads to finish.

BTW, I wouldn't worry so much about others...sometimes you have to reboot, etc.! If people are paying attention to their downloads, they will restart them if they stop. Sometimes it takes me days to get a file I want, but who am I to complain if I am getting a file for free while sitting on my butt? I do get frustrated, however, when I download 50% of a file, and for the life of me cannot DL the rest of it, even though I try for days on end. The file most likely is not being shared any longer. Oh well. It sounds like you share more than your share ha ha...

Have a good one