What this has to do with scams, I'm not sure, but some of your information isnt really correct.
First off, firewalls are often unnecessary if you're behind a decent router ( almost all of which have a hardware firewall built-in ). Firewalls dont play much of a part in preventing spyware and the like, and many use up a ton of system resources. Next, torrents aren't necessarily bad. Just make sure to get them from a reputable tracker, not something like mininova or other public sites. Also, one of the most important things that you didnt mention was keeping Windows up-to-date. That will remove alot of the vulnerabilities that allow mal-ware in your PC in the first place.
The best tip I can give is to keep your important stuff backed up, and do a format/reinstall of Windows every 6 months. This is the only fool-proof way to clean your PC. Otherwise, good guide.