Thanks everyone for your advice. Not only did I find out more about slicks, but learnt a valuable lesson on tuning my chisels to my needs. I ended up grinding a radius on the bevel side of my two inch one. I think it still needs a little more curvature; I'll work on that.
After some more frustration with my little, good-for-next-to-nothing tools, I ended up ordering the mortising ax I showed you earlier on. I quite like the wooden handle, and the fact that I can always turn it into a froe when my nerves fail me for good. I'll keep looking for that real broad mother of a slick. Knowing myself, I will eventually obtain every tool known to man as far as the state of my finances admit. However considering my mortgage, that day won't be dawning anytime soon.