No need to reinvent the wheel. Use Boot Camp to install Windows. Then:

1) You'll have the nice smooth, native graphics rendered in DirectX.
2) You'll have LOTS more options as far as keyboard broadcasting software. (Keyclone!)

I 5-boxed on a Macbook Pro until about 63 (when I needed to start entering Shattrath City), and I wouldn't even think about going back after seeing the performance difference on a "built" Vista machine.

Edit: Going from Mac OS Leopard --> Windows XP 32-bit, I noticed a +20FPS upgrade once I was in Windows using DirectX. The MBP I used had the 8600M GT, and my video options went from maxing out at 4x Multisampling --> 8x Multisampling and looked SOOOOO much better in Windows. Been there, done that. Just install it!