First, King James had nothing to do with the translating of the King James Bible except authorizing it.
Second, 'favored' is used by the NASB and the NIV as well.
You admit that it is a possible translation.
Third, the word 'favored' simply means blessed anyway.
The real issue is did Mary need a saviour (not being born sinless).
She stated that Christ was her saviour (Lk.1:47).
The only other place the word form is used in the New Testament is Eph 1:6 "To the praise of the glory of his grace, wherein he hath made us accepted in the beloved." The phrase "made us accepted" is the same word form. This is flat wrong and betrays somoene who is not reading Greek, but does not mind lying about the Gospel. I'd like to know who your source is, so we can avoid that author. "eis epainon doxes tes charitos autou en e echaritosen emas en to egapemeno" (Eph 1:6). Check for yourself at Unbound Bible. "Kecharitomene" does not appear anywhere else in the New Testament.
A Roman Catholic talking about a Protestant lying about the Gospel!
LOL!
Now what does Mary have to do with any Gospel, except a false one?(Gal.1:6)
I know. And his need was to create an English translation that is as anti-clerical as possible, so he authorized to put all the accents accordingly. Priests became "elders", and everything to do with Mary, as a type of Christian Church had to be trivialized. Luke 1:28 is not the only mistranslation. John 2:4 is another. John 19:27 is another.
'favored' simply means blessed anyway
The intent is to trivialize the blessing. "Grace" is a theological term that has specific meaning of cleansing of sin. "Favor" does not have such connotation. Besides, you are right, "favored" is roughly synonymous with "blessed", but she is also called "blessed" directly in the same phrase, so King James' translation of "favored" is flat redundant.
NASB and the NIV
Yes, many translations follow King James Version. So, avoid them too, and read Douay-Rheims if you cannot read Greek or Latin.
The real issue is did Mary need a saviour
That is not the issue at dispute; of course she did, and Christ is her savior too. He saved her at the moment she was conceived. This is why it is called Immaculate Conception.
A Roman Catholic talking about a Protestant lying about the Gospel!
Protestantism began with a lie about the Gospel (Roman 3:28, to be precise, was intentionally mangled by Luther, because the only way he could "prove" his Sola Fide fantasy was to commit fraud).
what does Mary have to do with any Gospel
She has everything to do with it (Luke 11:28).