Literally stop being paranoid and do it. Prosecuting individuals for reproducing copyrighted material is almost never enforced unless you're directly angering the copyright holder.
"security" in /Linux distributions is using up-to-date software and having common sense OPSEC. I suggest you read up on the computer science of torrenting first and then pick your preferred libre bittorrent client with a VPN.
Sorry if I sound a bit standoffish but you have to rid yourself of the idea that there exists a "secure linux os." The only increased security with libre software is your own knowledge and know how.