I agree that the faithful should be able to assist and advise a priest in matters that, for one reason or another, they have more competency and ability, but the leadership of the parish always rests in the hands of the pastor.
For example, I would desire greatly to be a liturgical resource for my parish. We have only one priest, our pastor, and it would be very hard for him to take the time to review all the liturgical matters (and documents!) which would help us celebrate the liturgy more reverently and faithfully to the prescriptions of the Church.
I admire your desire to serve.
But I don’t think that anyone in the Church should take on any task without the authority to do the task.
In our diocese, Catholics who are in ministry are required to complete two years of Ministry Formation. From what I understand, the course is not fluff and stuff. I know university professors who have gone through it, and it puts hair on your chest. Tons of reading and homework, and several lengthy papers to write, along with weekly classes and several retreats.
When a person completes their Ministry Formation, they are commissioned (I’m not sure if I’m using the right word) by the bishop himself for service.
In other words, they have authority to actually do their ministry.
There are many ministries that don’t require this much training, but there is still a declaration of “authority” to do the ministry. E.g., I am a pianist at two parishes. I have been hired to do this at one parish (by the pastor), and in the other parish, the Liturgical Director, a hired staff member with authority invites me to play (volunteer).
From what I understand, if a Catholic wants to start a Bible study, a club, or any kind of ministry that invokes the name of the Catholic Church, they are required to get permission from their priest and depending on the ministry, permission from the diocese.
I hope I am making myself clear. While in Protestant churches, people will just “step up” and take on a ministry, this shouldn’t be allowed in the Catholic Church. The people in ministry should be somehow “vested” and given permission and authority to do their ministry. Otherwise just anyone can “step up” and there is no guarantee that they will be qualified to do the ministry.