Questions about Fox one, fox two etc..

First off, why "fox"? "Fire one" - "F- One" - "Foxtrot One"- "Fox one"?

Secondly, in "Sea Harrier Over the Falklands" Ward describes Fox 2 as
denoting a missile launch from astern the target at one point and a heat
seeking missile launch at another (which could presumably be head on with an
AIM9L). From what I have read about SEA, it seems to me that "Fox 1" was
used when launching a Sparrow/SARH and "Fox 2" when launching a 'winder/heat
seeker, and "Fox 3" for guns. Is this generally correct? What would an F 14
pilot call when launching a phoenix? Fox 1, I presume.

Finally, why make the call at all? It seems redundant - the chap being fired
at will know soon enough, and it isn't really anyone else's concern is it?
(or if it is, there isn't much they can do about it)

Just wondering...