Well, call me skeptical, but I usually don’t put stock in any private revelation that usually combines commands from our Lord, our Lady, or whoever with quantities and legendary anecdotes.
The Rosary is good and powerful. Anecdotes like these, I seriously have my doubts (a lot of them actually sound, on the surface, to contradict authentic Catholic teaching, e.g. good deeds outweighed by sins. That’s not how salvation works).
If one wants a real, magisterial document on the Rosary, Rosarium Virginis Mariae by Pope St. John Paul II is the way to go. No one writes it like the saint.