To be honest, if you’re following every step you should feel pretty safe. That said, following every step is going to take up a lot of your system resources and will probably really slow down most older (and even some newer) PCs. Just remember to practice safe surfing whenever possible, and when you’ve downloaded a questionable bit of data, give it a scan before you fire it up.
If you only stick to a few sites, and don’t stray to questionable ones, you should be safe without too much extra software. Other than Firefox, I don’t have too much else running (in regards to antispyware apps) because of this. Actually, NoScript wasn’t mentioned, and I think it’s great!