Sorry to hear about your speakers. To be honest, I wouldn't know where to start to help you with that. Is it possible to disable a device such as the speakers in OSX? I haven't had it long enough to know. Potentially, there might be something jammed into the sound output jack that is causing it to disable to speakers...
But I can suggest a torrent program: Azuerus. I use it on both the PC and the Mac and find it quite useful. Don't know if you can get it without the Vuse bloat though.
Torrent files themselves are platform independent, kinda like Zips archives. As long as you have a client for them, you don't need to be concerned about whether the torrent is compatible. That said, the files inside the torrent can be Mac or Windows only (really only applies to programs).
Sounds like your mouse is broken, hardware wise. If you can, try connecting it to another Mac and verify that it doesn't work before you buy a new one though. I doubt it's a software issue, but weirder things have happened.