Juggling, seeker:
Good to have a chance to explain. It is a bit complex...
Apostolic succession and the doctrine of infallibility are separate though related ideas.
The former need not imply the latter. Most C of Es believe in the former but NOT the latter.
The former simply means the idea that each Bishop of Rome takes on the authority granted to Peter by Christ, when Christ said 'upon this rock I will build my church' - this is actually a pun on Peter's new nickname, Petrus or Rocky... and 'what you hold bound on earth I will hold bound in heaven.'
Papal infallibility applies only to a very VERY few pronouncements, seeker. The latest is actually the assumption of Mary, and as far as I know there has NEVER been an infallible pronouncement on the theology of the body. It's usually a weapon against serious schism.. so the following are the most agreed instances:
"Tome to Flavian", Pope Leo I, 449, on the two natures in Christ, received by the Council of Chalcedon; [against the Arian heresy]
Letter of Pope Agatho, 680, on the two wills of Christ, received by the Third Council of Constantinople;
Benedictus Deus, Pope Benedict XII, 1336, on the beatific vision of the just prior to final judgment;
Cum occasione, Pope Innocent X, 1653, condemning five propositions of Jansen as heretical;
Auctorem fidei, Pope Pius VI, 1794, condemning seven Jansenist propositions of the Synod of Pistoia as heretical;
Ineffabilis Deus, Pope Pius IX, 1854, defining the Immaculate Conception;
Munificentissimus Deus, Pope Pius XII, 1950, defining the Assumption of Mary.
Can't see that these are likely to outrage or even interest most outside the RC church 
Therefore it is perfectly possible to be a very devout catholic and to disagree a LOT even with ex cathedra statements, though normally such disagreements should be private. (Ex cathedra is NOT btw the same as an infallible pronouncement at ALL.)
If anyone is still awake interested I can rant on some more about ex cathedra.