Teachings that contradict Biblical truths are rejected. Practices that are forbidden are rejected. Links back to the ancient churches are cherished. Not on Mary....the RCC says she is sinless in contradiction to the Bible. I don't believe Mary was sinless. What's your point again? I don't believe she was sinless either. However, the RCC teaches that she was.
The Bible, if one reads it, will substantiate that she was a sinner and in need of salvation like the rest of us.