Dedicating a separate machine to piracy is a good idea.
For one, it can be always on and get you much better seed ratios.
It is also much more malware secure. As long as you back up any content on it regularly you can open everything you download on that pc first to see if it's legit. If it ends up infecting it badly you can just wipe the OS and start over without worrying about losing your main pc.
Also, legally, it is much easier to set up a VPN for the entire PC that ensures your ISP can't see your "gray" traffic, without impacting your normal computer experience (vpn's have bad latency) or having any accidental leaks (turn off vpn to play a game, forget torrent client open, bam you have 5 new DMCA cease and desist letters in your mailbox). It's just generally safer to compartmentalize.