I meant to say "gameboard", like http://www.amazon.com/gp/product/B001NEK2GE/ref=pd_lpo_k2_dp_sr_1?pf_rd_p=486539851&pf_rd_s=lpo-top-stripe-1&pf_rd_t=201&pf_rd_i=B0000ALFCI&pf_rd_m=ATVPDKIKX0DER&pf_rd_r=1KSVW0R6FPBDGXA3D4HD, which allow you to still use a mouse. Earlier models that I have seen just offer a D-pad with a small joystick on it, rather than a true anolog stick with variable input. I'm not even sure if the G13 has a true anolog or not, but I have seen some gameboards with one.

No. A set of keys, a, s, d, left alt, in my case allows movement in any direction without affecting my view at all. I can do rolling 360s while moving in any direction. I can look all around while maintaining my directional motion. My ability to jump sideways while turning to bring whatever into my sights makes me hard to hit while my ability to hit you is very little impaired. No chance.

A controller almost completely cripples any FPS game.

The movement with a key-set becomes very intuitive quite quickly. I have been doing it for some 17 years now though.