Right, Bearshare sets the my documents folder by default, and also turns "allow uploads" on by default. I don't agree with either decision, but I can understand it. If everyone that used Bearshare turned off uploads, there would be no Bearshare. It's kind of the point.
You can disable the spyware Bearshare comes with by installing a firewall like Sygate personal Firewall. Any program that wishes to access the internet from your computer has to go through the firewall. You can choose to allow them access to it or not. When you install Bearshare, allow Bearshare to access the internet, but all that other stuff, just say no to it. Bearshare will continue to work. It's an independent program of all the spyware.