Your rcia/Catechism is lacking, the Eastern Orthodox churches have Apostolic succession recognized by the Catholic church. They ARE both churches founded by Christ whether you think so or not. Your opinion is not shared by the majority of true Catholics.
No this is wrong and heretical and has been condemned by the catholic church in the councils and Papal Decrees. This is branch theory. Only the catholic church is the church of Christ.They may have apostolic succession but they are objectively a schismatic body hence they are not in our communion.
Ecumenical Councils
There is but one universal Church of the faithful, outside which no one at all is saved.” (Spoken by Pope Innocent III, Fourth Lateran Council, 1215.)
Council of Florence (A.D. 1438 – 1445)
“[The most Holy Roman Church] firmly believes, professes, and proclaims that those not living within the Catholic Church, not only pagans, but also Jews and heretics and schismatics cannot become participants in eternal life, but will depart `into everlasting fire which was prepared for the devil and his angels’ (Matt. 25:41), unless before the end of life the same have been added to the flock; and that the unity of the ecclesiastical body is so strong that only to those remaining in it are the sacraments of the Church of benefit for salvation, and do fastings, almsgiving, and other functions of piety and exercises of Christian service produce eternal reward, and that no one, whatever almsgiving he has practiced, even if he has shed blood for the name of Christ, can be saved, unless he has remained in the bosom and unity of the Catholic Church.”
(Spoken by Pope Eugene IV at the Council of Florence)
Popes
Pre-Vatican II
Pope Boniface VIII
"We declare, say, define, and pronounce that it is absolutely necessary for the salvation of every human creature to be subject to the Roman Pontiff.” ( Bull Unam Sanctam, in 1302 A.D.)
Venerable Pope Pius IX
“The Church is One, Holy, Catholic, Apostolic, and Roman: unique, the Chair founded on Peter … Outside her fold is to be found neither the true faith nor eternal salvation, for it is impossible to have God for a Father if one has not the Church for a Mother.”
Pope Saint Pius V
“He Who reigns on high, to Whom is given all power in Heaven and on earth, has entrusted His Holy Catholic and Apostolic Church, outside which there is no salvation, to one person on earth alone, namely: to Peter, the Prince of the Apostles, and to Peter’s successor, the Roman Pontiff, to be governed by him with the fullness of power.”
Pope Pius XI (A.D. 1922 – 1939):
“The Catholic Church alone is keeping the true worship. This is the font of truth, this is the house of faith, this is the temple of God; if any man enter not here, or if any man go forth from it, he is a stranger to the hope of life and salvation….Furthermore, in this one Church of Christ, no man can be or remain who does not accept, recognize and obey the authority and supremacy of Peter and his legitimate successors.” (Encyclical, Mortalium Animos)
Pope Pius XII (A.D. 1939 – 1958):
“By divine mandate the interpreter and guardian of the Scriptures, and the depository of Sacred Tradition living within her, the Church alone is the entrance to salvation: She alone, by herself, and under the protection and guidance of the Holy Spirit, is the source of truth.” (Allocution to the Gregorian, October 17, 1953)
Post-Vatican II
Pope Saint John XXIII
"Before everything else, fidelity to the Church: One, Holy, Catholic, and Apostolic. Jesus did not found several churches, but one single Church. "
Pope Blessed Paul VI
“The Catholic Church alone is the Body of Christ, of which He is the Head and Savior … The “People of God” and the “Mystical Body of Christ” are one and the same thing, both of them designating The Church … Do not all those who are baptized belong to the Church? And is not the Church only one Church? Yes, but membership in the Church requires conditions other than baptism alone; it requires identical faith and unity of communion, so that … by means of the Catholic Church alone, which is the unrestricted instrument of salvation, is it possible to obtain the fullness of means to salvation … The Church, and the Church alone, possesses the secret of true relationship to God as established by Jesus Christ. Indeed, the Church is this very relationship, which is both a certain and an exclusive means of attaining salvation… Those who are enemies to unity do not participate in the charity of Divine Life; those outside the Church do not possess the Holy Spirit …The entrance to salvation is open to no one outside the Church!”
** Servant of God. Pope John Paul I**
" The Ship of the Church is guided by Christ and by His Vicar … It alone carries the disciples and receives Christ. Yes, it is tossed on the sea but, outside it, one would perish immediately. Salvation is only in the Church; outside it, one perishes."
Pope Saint John Paul II
“As a sacrament of intimate union with God, the Church is in Christ, outside Whom there is no salvation.”
…"…
