Orthodox Catholics and orthodox Presbyterians both realize that about the only joint "liturgy" they could share would be a common recitation of the Lord's Prayer and the Apostle's Creed.
I would point out that Catholics also believe in the priesthood of all believers.
The distinction is that Catholics believe that there is a common priesthood and a sacrificial priesthood whereas Presbyterians do not believe that there can be a sacrificial priesthood.
In practice, any adult Catholic male - married or unmarried - can, if called to the order of deacon, perform the role that Presbyterian pastors are called to perform: preside at baptisms, solemnize marriages and burials, communicate the people in the Lord's Supper (not consecrate the Eucharist, but Presbyterians do not acknowledge a consecration), proclaim the Scriptures from the pulpit and preach God's Word.
I appreciate your clarification of some distinctions. I would agree with you that the groups involved are not orthodox.
I am looking forward to the gathering of believers where this disagreements will be resolved and true fellowship will be experienced.
>>>>In practice, any adult Catholic male - married or unmarried - can, if called to the order of deacon, perform the role that Presbyterian pastors are called to perform
In the absence of a priest or deacon, any lay Catholic has the right to baptise a dying man, and offer him his last rights. I have heard of many cases in hospitals and in battlefields, where ordinary Catholics received dying people into the Catholic Church.