Who doesn't agree is not a Christian.
You cannot have continuing revelation and no Church hierarchy.
That is the absolute story of the entire Bible. You cannot read it any other way. Why accept Moses? If you accept Moses, why accept Aaron and Hur? Why accept Joshua or the judges? Every revelation of God and restoration of his Gospel starting most clearly with Moses comes with a delegated authority from God and a hierarchy, formally placed by God or those with the proper authority to do so. You cannot find an exception. If you act in God's name without authority, you'll see that the penalty is severe: see Uzziah's entrance into the Holy of Holies, etc.
There's really very little hierarchy in the New Testament (between the churches; within we see bishops, pastors, and teachers mentioned), certainly compared to the Catholic church (and most protestant denominations) — this is to say that the early churches were meant to be largely self governing and, incidentally, why Jesus's messages to the Churches in Revelation were addressed to particular churches.
Only partly true as your link to Titus clearly demonstrates, read it for yourself. Paul shows authority, command, and direction over the Church. That's delegated authority coming from God. Why listen to Paul otherwise, because he's popular and a good speaker? That's not God's criteria - see David's selection for the specifics.
Who can appoint a Bishop and what is the methodology? That is how specifically is a bishop, pastor, evangelist called and set apart unto that calling?
What is the laying on of hands and when do you anoint with oil? See Exodus 28:41 and Exodus 30:30 and James 5:14. What are the specific circumstances calling for an anointing? How about casting out devils/demons and anointing for the sick? See Mark 5:16. What is the method there?
This isn't to say there is no [inter-church-group] hierarchy and that there was no deference of younger churches to the elder — the council at Jerusalem [Acts 15] proves that false — but even that council acknowledged the Holy Spirit as guiding them.
Please reread Acts 15. Who appointed Paul and Barnabas? Peter acts as head of the Church and that's clear from James' reference.
If not, then I think you have to convince me.
Jesus Christ is the God of the Old Testament and it testifies of him. Interestingly the title Jehovah, means "I will be that which I will be" meaning no man will define me. The NT does the same, only now it makes distinctions and clarifications, yet it's the same Church from the beginning.
I need not convince you. Convince yourself. It's all there in the Bible. There is an absolute need for proper authority in the Church to act in the name of God. That's not splitting hairs, it's the message. There's nothing arbitrary or random in God's Church.
Jesus did to be an apostle and the people in the assembly at Antioch appointed them to go to Jerusalem to meet with the apostles because of the dispute.
>>Peter acts as head of the Church and that's clear from James' reference.<<
Peter was simply on of the speakers as were Paul and Barnabas but it was James who made the ultimate decision and statement.
The role of Priest?
Oddly enough every Christian has that role.
(1 Pet 2:9)
But you are a chosen race, a royal priesthood, a holy nation, God’s own people, in order that you may proclaim the mighty acts of him who called you out of darkness into his marvelous light.(Rev 5:9-10)
They sing a new song:
“You are worthy to take the scroll
and to open its seals,
for you were slaughtered and by your blood you ransomed for God
saints from every tribe and language and people and nation;
you have made them to be a kingdom and priests serving our God,
and they will reign on earth.”(Heb 4:14-16)
Since, then, we have a great high priest who has passed through the heavens, Jesus, the Son of God, let us hold fast to our confession. For we do not have a high priest who is unable to sympathize with our weaknesses, but we have one who in every respect has been tested as we are, yet without sin. Let us therefore approach the throne of grace with boldness, so that we may receive mercy and find grace to help in time of need.