Ahhh yes! I actually know exactly the movement that you mean! You just cant stop movin' or you die, but too long straight to any direction leads to a death. It's just jerking random movements.
I've tried now with cryo + orbital + point defense (+ rail gun for bosses like you said), and it's proving to be surprisingly good. Unstable core, of course, is a prio always - sometimes even when on critical hull.