I've cracked a couple of blades using the hammer, but would not give it up. As I see it, the key is not to try to bend the blade with the hammer, but to spread out the material on top a bit, so when I'm striking the blade, the anvil is always directly below the hammer.
I've been told that hammering blades cold can actually make the steel harder. You never know what to beleive, just have to try stuff and use what works. The thing I am confident about is that you do have to sharpen the back just like the bevel, in other words, your finishing stone must be hitting the end of the edge full on.

I prefer to have my chisels and slicks flat on the back, and will often hollow grind the center of the back as well, like a japanese chisel.