Frankly, with the exception of the two defaults of using the Limewire MP3 Player and being an ultrapeer, I would leave all the defaults untouched in the Preference boxes. Although tweaking and fiddling at the margins can often be a good learning strategy, it won't help you much here. Your machine and your "habits" will be noticed and dispassionately recorded by the ultrapeer machines. The more you share and the more reliably others are able to upload from you, the more your machine (and its user) will earn respect. It's a quid pro quo kind of thang. However, even that would be irrelevant so long as you remain a leaf by choice. And, in all seriousness, there are some performance issues for the developers to resolve for ultrapeers and you will be safer as a leaf until then, even though it does marks you down as less than completely sociable. But, in the wider pool of Gnutella, the majority of unthinking and uncaring users will be oblivious to this minor blemish on your escutcheon.