Does a validly baptized heretic remain in the Body of Christ? No.

Blind Fool

You are truly ignorant and blind.  You don't know what you are talking about at all.  The Catholic Church teaches that you must profess the true faith to be in the Body of Christ, even if you are validly baptized.  It teaches that heretics (who by definition are baptized) are OUTSIDE THE BODY.  It teaches that people who reject the Papacy (or any dogma) are OUTSIDE THE BODY OF CHRIST.  Here's some proof for you, blind fool:

Pope Eugene IV, Council of Florence, Bull "Cantate Domino," 1441, ex cathedra: “It [the Holy Roman Church] condemns, rejects and anathematizes all thinking opposed and contrary things, and declares them to be aliens from the Body of Christ, which is the Church.”

Pope Pius XI, Mortalium Animos (# 11), Jan. 6, 1928: “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.”

Pope Leo XIII, Satis Cognitum (# 9), June 29, 1896: “So, with every reason for doubting removed, can it be lawful for anyone to reject any of those truths without thereby sending himself headlong into open heresy? without thereby separating himself from the Church and in one sweeping act repudiating the entirety of Christian doctrine?... he who dissents in even one point from divinely received truths has most truly cast off the faith completely, since he refuses to revere God as the supreme truth and proper motive of faith.”

Pope Pius XII, Mystici Corporis Christi (# 23), June 29, 1943: “For not every offense, although it may be a grave evil, is such as by its very own nature to sever a man from the Body of the Church, as does schism or heresy or apostasy.”

Like Madrid, you are not Catholic.  You are in the Vatican II Sect.