I dunno. Seems to me that there are two greetings in latin: 'salve' and 'ave.' Just from the two prayers we know utilizing them, one could conclude that 'salve' is the greeting used by an inferior, (or to establish one's humility vis-a-vis the one who is greeted), whereas "ave" is used by one who is superior.
Ave, imperator! Morituri salutamus!
"Salve" is the imperative form of the verb "salvere", which means to be in good health, to be well, salvation, etc. The imperative form is the form of a command or request. Salve happens to be the singular imperative.
"Imperative is used to express a command"
http://www.dl.ket.org/latin1/review/faq-imperative.htm
So when we use "Salve" as an imperative of the verb "Salvere", to a normal person we are telling them "be well". But Blessed Mary is already quite well and cannot change. The only sensible translation has to do with salvation, it is a command to "Save!"
"Save, O Queen, our life, our sweetness, and our hope, save! To thee do we cry, etc." The prayer would make little sense if we were commanding "Be well, O Queen, etc." when we then go on to petition all manner of mercy and eternal life from her, i.e. "show unto us the blessed fruit of thy womb Jesus".
The word "show" in the prayer, "ostende", is another imperative command, from the verb "ostendere", "to show, to offer". Similarly, the word "converte" is the imperative of "convertere", "to turn". If we all agree that literally is a command to Mary to "turn" and to "show", how is salve not a command to "save".
Yes it is a greeting, but dig deeper and ask yourself who and in what manner you are greeting!
Exactly the same meanings as the German "heil", from which "hail" comes from.
Heil Dir, Königin, Mutter der Barmherzigkeit,
Leben, Süssigkeit und unsere Hoffnung, heil Dir!
Zu Dir rufen wir verbannten Kinder Evas,
zu Dir seufzen wir, schluchzend und weinend
in diesem Tränental.
Ach, nun also, unsere Fürsprecherin:
jene deine barmherzigen Augen
wende uns zu,
und Jesum, die gesegnete Frucht Deines Leibes:
zeige uns nach dieser Verbannung!
O gütige, o weiche, o süsse Jungfrau Maria!
But where does that leave this?
Ave Regina cælorum!
Ave Domina angelorum.
Salve, Radix. Salve, Porta
Ex qua mundi Lux est orta.
If your theory were true, Ave Maria would be an atrocious thing to say.