Any person can baptise (technically speaking) as an extraordinary minister of the sacrament… which is why protestant ministers can baptise.
As to marriage, the ordinary minister of the sacrament are the participants themselves (the husband and wife). The minister serves in the role of a witness from the church, which is required for Catholics getting married, but not for non-catholics. In other words, the pastor doesn’t have powers of ordination beyond that of any layperson because they are not validly ordained in the eyes of the church.
That is untrue. Any layperson can ASK that God blesses somebody. In the catholic church, however, we know that our priests are given authority as Christ tells His ministry that “He who hears you, hears Me” and that whatever they “bind on earth will be bound in heaven”. The Catholic Priest, and ONLY the catholic priest can say “I give you the blessing of God” and allow us to be assured that God has indeed and without doubt blessed us in accordance with His words to His church.
In other words, only a validly ordained priest has the authority to GIVE blessings. All the rest of us, including invalidly ordained ministers, only have the authority to ASK for blessings and HOPE that they come along.
This is not necessary. We are not to make a scandal by any form of participation at protestant worship services. We are allowed to attend ONLY as observers to avoid giving the perception that we validate their opinions or hold them as our own. Furthermore, since we DON’T believe in their rites or creeds, it would be absolutely disrespectful to pretend that we do and to receive them as though they are only hollow gestures and we don’t care.
We honor the sincerity with which protestants practice their faith by behaving as respectful observers ONLY.