Wow...I had no idea you could do that. I just use my mouse and proper timing of shield regen vs. blaster boost. I'll have to try this, but usually I do just fine using only a mouse.
The first few times I was doing the heroic missions, I relied entirely on mouse targeting/avoidance (which cut down *very heavily* on my attack uptime considering the incoming damage) and (ab)using the Conversion Module/EMP/ECM, but couldn't often manage to get full clears on all of the bonus missions and often scraped by with only a sliver of armor left. As soon as I started using WASD, I started clearing all of the heroic space missions without ever really taking any damage. The WASD isn't really *required*, but it makes those missions *so much easier*. The only thing I *don't* use is the barrel roll, and that's because I'm pretty sure it doesn't actually do anything except look slightly amusing.