I can answer your hostile question at least on a superficial level. There is a file called hostiles.txt which is at the top level of build tree, to quote the comments in it, it is "provided by BearShare". I note that in it are included IP's which I had noticed (and thus filtered out) were providing multiple hits on many queries (<search term>.html <search term>.mp3 <search term>.jpg, etc.). I took the list and blocked them at the iptables level (iptables -IINPUT -s$host -j DROP), as it seemed good to stop them even before gtk-gnutella.