homebrew is just the name used for non Sony programs.. so can be anything from hacks for games to running unix on it..

yep games are best from bittorrent and torrent clients are easy to use..

http://azureus.sourceforge.net/ is easy to use just need java as well from http://www.java.com/en/download/manual.jsp

and that trojan will only run if you choose to run it.. so if your that daft you deserve it IMO