Strictly speaking AoA and Cl are reciprocal functions of each other - i.e. a change in one will result in a change in the other.
I take it you don't mean us to take reciprocal literally? Complementary perhaps?
Agreed - but because of the relationship between AoA and Cl and the V(elocity) component of the Cl calculation there is an indirect relationship between airspeed, thrust and AoA - that's all I've been saying.
Again, not quite - normal acceleration is just as important
But there we get into the quasi-religious aspect of pilot authority. While it would be possible to do such a thing, those who consider the Airbus FBW and modern FMS as a step too far* would likely kick up a hell of a stink.
There I don't agree - adopting a default value for the stall warning AoA threshold for use when a genuine Mach value is not available does nothing to limit the pilot's authority. It might let him go further into buffet before calling halt at high M and be more restrictive than it need be at low M (until flaps/slats are extended, at which time it can be made indistinguishable from the value it would have if Mach were available), but it would certainly give better guidance than they get today.
PS: It's getting late and I need to check, but I seem to remember that the stall warning AoA already defaults to something like 10 deg when no Mach is available (Hazlenuts?)