> I use mouse1 forward, mouse2 back, z right, x left...
How do you fire?
There's an article in a recent UK PC Gamer in defense of using the cursor keys instead of WASD. There's a certain logic to it, but for most games there just aren't enough keys near to your movement directions to easily perform all the functions the game allows.
These days I'm using Q and E to cycle through my inventory. It works really well. (I've never been much of a leaner).