What you submit is not new, here and elsewhere a genuine attempt at a relationship between Catholics and Protestants. (So your thinking along these lines has good company. Hurrah!!!) What sometimes mucks it up is when issues like some of the now banned posters, (both here and on other boards) make attacks, and unsubstantiated claims. An honest and careful reading of history will show that the Catholic Church has always been open to such union as long as it is held in an honest manner.
We have already discussed the Church offering protection to and from the Council of Trent (and other Councils, and church meetings) to Luther and other Protestants to explain their new teachings. The Catholic Church cannot be condemned because Luther and the others did not take the Church up on the offer. Don’t forget this offer was made publicly, and if the Church had not followed through on the promise, it would have won more sympathy for Luther than for the Church.
As an example, just last month was the Octave of Christian Unity. The Week of Prayer for Christian Unity began in 1908 as the Octave of Christian Unity, and focused on prayer for church unity. The dates of the week were proposed by Father Paul Wattson, co founder of the Graymoor Franciscan Friars. He conceived of the week beginning on the Feast of the Confession of Peter, the Protestant variant of the ancient Feast of the Chair of Saint Peter, on 18 January, and concluding with the Feast of the Conversion of Saint Paul on 25 January.
Pope Pius X officially blessed the concept, and Benedict XV “encouraged its observance throughout the entire Roman Catholic Church.” For a while, the observance was re-named the “Chair of Unity Octave” by Wattson, in order to emphasize the relationship between Christian unity and St. Peter and his successors. Fr. Wattson, by the way was a former Episcopalian, who established a Franciscan Order for men and one for women in the Episcopal Church, and later around the turn of the last century, the entire group entered the Catholic Church, and was allowed to continue their order as Catholics, Fr. Wattson and a few of his other converts being ordained as Catholic priests. The Graymoor Fathers still exist and live in the same monastic community in New York.
Protestant leaders following the lead of the Catholic Church established in the mid-1920s an annual octave of prayer for unity amongst Christians, leading up to Pentecost Sunday. Since each Protestant group does not accept the teachings or authority of the next not all of them participate in this practice.