Roman Catholics are decidedly not Christian.
1. They claim to be the Mother Church that all other churches derive any legitimacy from at all because we ride their coattails to them.
2. They are not against saying that the eternity of Protestants will be painful because they are so in error. (remember they believe in purgatory)
3. All of those I have talked to downright hate baptist beliefs and think we are terrible sinners doomed to some sort of terrible judgment after death
4. They violate clear teachings of the bible that identify themselves as false Christians They violate so much I'll just refernce you to this website, even just picking out the bible verses and ignoring the analysis shows that Roman Catholic clergy are false teachers (21 Important Bible Verses About The Catholic Church)
Really #4 alone on such a consistent basis is all I need to say. They teach a Jesus of the Church. This Jesus is not the Jesus of the bible to nearly anyone who would disagree with Roman Catholic clergy.
This issue of Catholicism is a red herring because you said that this thread was about Mormon "martyrs" but you cannot name any of such Mormons or give specific examples of what you are talking about. Nothing personal, but I think that you took Mormonism at their word that Joe Smith was a martyr because they are trying to make you look away from his record of theft (his bank in Kirkland, OH), his time in prison in MO, and his gunfight in Carthage, IL after being arrested for sexual perversion in violation of marriage law against polygamy as well as his violation of Mosaic Law concerning marriage to sisters and to mother-daughters and his arrest for destroying the printing press of the newspaper that published the details of his depravity. This thread gives too much respect to Mormonism. Even Sherlock Holmes has a story about Mormon criminality in Utah--A Study in Scarlet.
A Study in Scarlet by Arthur Conan Doyle