A person can absolutely come to the conclusion that abortion deprives a person of their inalienable rights without any Church’s guidance.
The Church is made up of flawed men. I want these flawed men to enforce the truth of what the Church teaches, that abortion is baby butchery, and support for baby butchery is a grave sin that seperates one from the Body of Christ. I’m not sure what your problem is with that.
I'm not sure if clergy who permit pro-choice Catholic politicians, e.g., to receive communion are actually guilty of "supporting" the pro-choice agenda. According to Church teachings though, these politicians should be turned away.
I'm not sure what your problem is with that.