Chris:
RE:
SNIP If a guy throws a simple jab, cross, hook combo, for instance, footwork alone won't get you out of danger completely, even if you had the superhuman speed to match his hand speed with your footwork. SNIP
No, but as we are talking 'tai sabaki' not blocking, I will add that you CAN defend against a jab-cross-hook by simply bobbing and weaving.
But I broadly agree with all your points. Footwork, of course, has as many offensive uses as defensive, given that fighting is all about position and angle....well, in an ideal world, at least.