torrent is almost impossible to block. As you found out you must block hundreds of sites. Even then if they get the seed files from another source you can do little.
You might be better off blocking all ports for all sites to start and then add 80 and 443 and some of the other common ones as you need them. It would slow down a lot of this.
The other way is to use the opendns site and use their filters. The basic ones are free and the next level up that you can customize more are not real expensive. You need to block port 53 though to prevent the simple bypass of changing the pc dns. They can still bypass with the host table but it take more effort.
There really is no simple way to do this with a consumer router. You need one...