LW, FW and Bearshare are all using the Gnutella Network. Though Bearshare seems to connect to LW host clients better than vice versa.
Regarding the crap.....well, it's of users hosting the bad files, i.e. with Bearshare you'll ulimatively find the same bad files since they are hosted via the Gnutella Network. LW has a junk filter though, and when using it for a while the bad files will get less. The same is with FW afaik.
LW has a music player built-in. Go to LW>Tools>Options>Player and enable it.
