...the fact that Catholics believe you can buy your way out of sin...
Whoa, there, Martin Luther. Let's not get ahead of ourselves.
I know the church is hardly perfect and that there have been plenty of problems both past and present, but I don't believe the buying of indulgences has been an actual issue within the last couple hundred years.
We Catholics owe a debt of gratitude to Martin Luther for pointing out (vociferously) many of our old problems, but...
I'm pretty sure the Spanish Inquisition is over, as well. Want to blame present-day Catholics for that, too?
...the head of the church is the pope - not Christ
Who says? Again, I'm hardly a perfect Catholic, but I'm pretty sure nobody ever said "ignore this Christ guy--the pope's where it's at" at any point. Believe it or not, we Catholics are Christians, despite what various (misinformed) non-Catholic Christians might believe. We just have a larger bureaucracy :-)
Does the Catholic Church have problems? You bet. Tons. Most of them related to being a huge, largely-decentralized *, and very forgiving ** organization. We do *not*, however, believe in the sale of indulgences or in the non-primacy of Christ. If you insist on attacking us, please do so with at least 20th century problems, not with 14th century ones.
* - Each individual diocese has a surprisingly large degree of autonomy from Rome. Hence the reason some dioceses dealt with the pedofile priest problem better than others.
** - Believe it or not, both the Crusades and the Spanish Inquisition ended a long time ago. We tend to be a pretty forgiving lot nowadays.