I was wondering how to address non-Catholic ministers? I don’t know if it is appropriate for me to call them “Pastor.” I do have Protestant friends who refuses to call my priest “Father.” you please help?
You could call the minister what his congregants call him. If you don’t feel comfortable with that, it is perfectly correct etiquette to call a Protestant minister “Mister” (or “Ms.” if the minister is female). This, by the way, is basically what your Protestant friends are also doing: They could call a Catholic priest “Father” as an acknowledgment of what a priest is called by his congregation, but if they consider that a violation of their conscience then they call a priest “Mister.”