I'm following your discussion here with a certain kind of fascination. A very interesting topic with well weighed points of view.
It reminds me of a similar discussion right in the beginning after I became a member here, though the topic was not the assimilation of the torrent technique into the LW/ Gnutella clients.
I guess each of us has different philosophies and approaches. So, I'll reduce my comment to the point of freeloading, or leeching as you call it.
"Be fair and share" would be a logo everyone of us could agrees to.
But if sharing becomes compulsory or mandatory, can you still call it fair??
If your taste (i.e. the files you offer to share) do not fit the taste of others, would it be right to punish you (i.e. restrict you in your downloading capability due to a lack of uploading)??
Gnutella exists despite the freeloaders.
Merging LW with Torrents (or at least creating clients that support both ways) is the next natural step in the evolution of filesharing, and it won't be the last. Sooner or later those who are contra freeloaders (in both groups, gnutella users/ developers and torrent users/ developers) will see that despite the possibility only the minority will leech.
Further developments will go in the direction of supporting up and downloads to sites like rapidshare, megaupload and their likes. Or maybe the possibility to use one's file without downloading on your own computer (depending on the development of the internet speed).
Though just my 5-cent-worth
