Any steel spur requires a hardened clutchbell, I believe.
http://www.robinsonracing.com/catalog/revo33.html
I don't understand why they don't have a page for the Slayer. But there's also a couple spur clutchbell combos. Tower carries them as well.
Indeed, that's how you learn. When you get ready, get a Robinson Racing Gen 3 slipper unit. It's more expensive than a Traxxas unit or even a simple steel spur gear would be, but it's miles ahead of the traxxas unit. Just be aware that when you do you'll have to get a hardened clutchbell as well.