Please don't hold it against me, but I can tell. So, is my first sentence re: you and languages correct, or ad hominem?
Do you know what I mean when I speak of parsing? Do you know that different spellings of the same Greek verb simply indicate different tense, voice and mood, whether we're dealing with a verb, a participle, etc.., which all tells us what the word is saying precisely?
Here's the issue you have, chevy: The same word is used twice in the new covenant. The different spellings just indicate precisely what is being said about time, action, etc. Actually we're not even dealing with a root word yet. We're actually dealing with
the same word structured/spelled differently to tell us something just a bit different.
As I've said, Luke 1:28 is simply addressing Mary as one who
has been graced/favored at some time in the past and
is graced/favored at the time the angel addresses her. Nothing more, nothing less. She is certainly special as the one use of the word with that specific structure/parsing
may be indicating, and I doubt we'll find any reasoning Christian saying she is not. But, sinless? No. Not from this verse, or word, or any others any of us know of.
Mary is a bit troubled by the angel and what he says to her, so he clarifies in 1:30: You found
favor/grace with God. Aorist tense that in this context means the favor/grace of God was found in the past, which is again not specified precisely as to when. When we deal with root,
favor/grace in 1:30 and
favored/graced lady in 1:28
are both from the same root.
The other use of the word, as I've also said, is simply structured/spelled differently, because it is saying something just a bit different about the favoring/gracing being done, but
it's the same word and concept. Mary is being addressed as someone who was at some point
favored/graced, and is
favored/graced at the time the angel speaks to her. In Eph1:6 Paul speaks of the praise of God's glorious
favor/grace (same word as Luke 1:30) with which He
favored/graced (same word as Luke 1:28) us in The Beloved [Jesus Christ].
Mary was
favored/graced by God to bear the humanity of His Son. God
favored/graced us in His beloved Son.
If the single use of the word as structured would be used to run amok doctrinally, maybe our omniscient God gave us the Ephesians verse to put that doctrine in check. My speculation is as good as yours. Problem for you is it does just that even though it's just an assist. The word as Luke uses it doesn't say what you're trying to make it say. Nor does it say what the Latin translation says.