Hopefully, not for long. However, I am not an American Catholic, I am Catholic who is also an American (naturalized, in my case). The Catholic Bible is the Vulgate; the NAB is approved for liturgical use in the vernacular. I am not disputing a liturgical point of the vernacular; it is not likely that you are. The Vulgate says "poenitentiam agite". That is the accurate translation.
[Metanoia is] a change of heart which resulted in a change of life
Exactly. Quite often, the change of life includes oblations such as fasting and abstinence of creature comforts, -- see the monastic practices of two thousand years tat follow the pattern set by St. John the Baptist. "Must" (your contention in 6922, see word in bold) the life long work of conversion follow "formal public physical manifestations of repentance"? Well, no. No one is forced to be a monk. It is just a good idea. I will have a gereatwer repect for modern Protestantism when I see some asceticism voluntarily practiced.
saved in one day, as the 3k souls at Pentecost
When a Protestant says "saved" he often implies that the work of faith has been complete in that person. Do you imply that?
he NAB is the official Bible of the U.S. Conference of Bishops
Hopefully, not for long. However, I am not an American Catholic, I am Catholic who is also an American (naturalized, in my case).
Which in practical terms means?? Catholics can read that and other Bibles, in contrast to much of her history, but I do not think Rome would allow your condition to forsake the use of the NAB in Mass if you were a priest. But this is just one more thing which Catholics take issue with their church about, partly for legitimate reasons. The NAB impugns upon the integrity of the Word of God by its adherence to the discredited JEDP theory, and Catholics themselves have complained that it relegates numerous historical accounts in the Bible to being fables or folk tales, among other denials, along with other problems and gender inclusive language.
The USCCB owns the copyright for the NAB and the RNAB, and a Catholic podcast Lectionary even got a quick "cease and desist" letter for violating copyright However, their Bible text had to be amended for the lectionary because the Vatican rejected it for Mass no one in authority seems inclined to incorporate these same emendations back into the RNAB.
Also, the NAB footnotes assert alleged contradictions in Scripture, and Catholics are divided on whether the Vatican Two statement in Dei Verbum, which was the result of a behind-the-scenes debate at Vatican II about inerrancy, and states that the Bible “teaches without error that truth which God wanted put into the sacred writings for the sake of our salvation" supports the position that the Bible is only immune from error within a certain limited domain, which at least one frequent Roman Catholic poster here seems to think, if that, versus what Pope Leo XIII, Providentissimus Deus states. Of course, there is also disagreement as to whether all encyclicals are infallible, or how much therein is. Also debated is whether the Bible teaches geocentrism.
saved in one day, as the 3k souls at Pentecost
When a Protestant says "saved" he often implies that the work of faith has been complete in that person. Do you imply that?
If you mean a faith that is alone, having no fruit, and no growth in grace, then that is a superficial, if convenient, understanding, and you should have know my answer by now. If you mean that at that moment the person is washed, sanctified and justified, (1Cor. 6:11) accepted in the Beloved, (Eph. 1:6) spiritually baptized into body of Christ, (1Cor. 12:13), and translated into the the kingdom of God and made to sit together in heavenly places (Eph. 2:6) and would go to be with the Lord that day if he died, but who is to become more and more practically what he is positionally, to one toward completeness, yes.