Dan's questions are not his alone, there are many others looking for answers to the same or related questions. The answers I give here are my own and are based on my particular spiritual journey.
Priesthood - Dan writes,
But didn't they have priests in the Old Testament, and doesn't that carry into the New Testament with pastors? Not that we need priests, but pastors simply serve as "ordained" leaders.
Indeed there were priests under the old covenant, but almost everything changed when Yahshua returned to his Father in Heaven. As his body here on Earth, Jew and gentile, man and woman, slave and free, we have all accepted Yahshua as Lord and King. We are a royal priesthood, HalleluYah! We are all, therefore, priests. And priests serving under a High Priest of the order of Melchizedek (see Hebrews 7). In other words everything has changed, the old arrangements no longer apply. We are priests in Christ's line, not priests in Aaron's line.
What does this mean? If I am a priest and you are a priest, which of us has priestly authority over the other? There is of course the Great High Priest who is Christ, and he has authority over both of us. But we are obedient to him alone, not to one another.
And again, what is a priest? A priest is one who offers a sacrifice on behalf of others. But there is only one sacrifice, Christ the Lamb, who offered up himself. Everything is brought together in him, he is Sacrifice, High Priest, King of Kings, Head - but also Emmanuel, 'Elohim with us'. It's no coincidence that there are no priests and no Temple in Jerusalem today. We are the royal priesthood and the living temple.
There is simply no room in this new convenant household for a priesthood over the Lord's people. We are the priesthood!
Authority - If we can conclude that government and shepherding by elders and pastors cannot come from a priestly source, where else then can it come from?
Notice that I avoided the word 'authority' in that last sentence. I wrote 'government and shepherding' instead. Why?
Before discussing that I think we need to look at that word 'authority' in a bit more detail. There are two kinds of authority, two distinct meanings that we hold in mind when we use that English word. This has caused many people to become confused because the distinction is not often made clear. Let's think about two people - a policeman and a plumber.
Let's take the policeman first. What do we mean when we talk about the authority of a police officer? We mean that if he tells us to get out of our car, we'd better get out of the car. If we're wise we'll do it in good time and without arguing. A policeman has been given authority from above. It arrives via his sergeant, and on up through an inspector, a superintendent, and eventually right up to the Chief Constable at Police Authority level. (This is the British system, others will be similar if different in detail.) Ultimately that authority goes to the Home Secretary, and on to Parliament, and then to the Queen.
So when that policeman stops you, he draws upon all that hierarchy for his authority. The law is on his side.
Now lets look at the plumber. He has no authority in the sense that the policeman does, yet he is rich in another kind of authority. Suppose a pipe bursts in your kitchen and starts to flood the floor. You need a plumber and you need one quickly. This is the authority of knowing what to do, the plumber's power is not delegated, but he has the skills to help you when you're in a fix. If a policeman tells you to leave the car you do it because of the law. If a plumber tells you to leave the kitchen you do it because he knows something you don't!
Sometimes we say a person is a great authority on butterflies. We don't mean they have been invested with the right to order us around, we mean they are an expert and we would naturally call on them if we wanted to know more about a butterfly we spotted in the garden.
Paul makes it clear that he has in mind that second sort of authority for the believers. There was no delegated, hierarchical leadership in the early church. There were no priests, no paid clergy, it simply did not work like that!
Elders and pastors - When we read about 'elders' the Koine Greek word is 'Presbuteros' which really means an older, wiser, more mature person. This would be a person with the 'plumber' kind of authority, not in any way like a policeman and with no hierarchy to answer to. When the church was struggling with some issue (and there will always be issues!) they would naturally pay particular attention to these people. This is the 'double respect' that we read about, it does not refer to payment but to the regard such a person would be held in.
It's not hard to find these people in the church today. Look around and you can identify them in any group of believers that have been together for a year or two. They are often humble, quiet, gentle people. They don't parade their wisdom, but everyone respects them and listens when they express a view on something.
Similarly with a pastor (a shepherd). Jesus made a point of explaining the difference between a good shepherd and a bad one. Sheep are not driven by a shepherd, they follow because they know him.
We shouldn't be looking for appointments in the church, we should be looking for functions. Let's begin to recognise the elders and pastors (and prophets and teachers and the rest). They're there in every congregation, in every cell group, in every house church, wherever two or three are gathered in the name of Yahshua. Look and you will see them.
Submit and obey - Hebrews 13:17 is very interesting. I've looked hard and long at the Greek words translated 'obey' and 'submit'. They need not be as strong as they appear from those English words. 'Obey', for example has something of the meaning of 'defer to' or 'allow to persuade'; and 'submit' carries the sense of 'yield', or 'allow room'. It's also worth mentioning that the Greek contains no word for 'authority' in this verse, it's simply been inserted in translation.
The idea of leading or leaders is rare in the Bible except in connection with the state or the army or the priests (look up 'leader' and 'lead' in a concordance and look at the contexts). The word translated 'leaders' here is one of those rare occasions. Personally I'm not clear how to understand this verse, I'd be glad to hear from any Koine Greek scholars out there who would care to explain the range of possible interpretations.
My best guess is that the verse either means, 'Obey your leaders and submit to them because they watch over your souls as those who will be held accountable', or alternatively it might be translated, 'Be open to persuasion and give way to those that lead because they watch over your souls as those who will be held accountable.'
The reason I wrestle with this verse is that in its usual translation it doesn't seem a good fit with the rest of the letters to the churches, not does it sit well beside Christ's teaching. He said, for example, 'You are not to be called Rabbi (Teacher) because ... you are all brothers' (Matthew 23:8).
This doesn't cover everything that you raised in your post, Dan, but I hope it helps with some of the points. At any rate, this is more than enough for one blog post! Maybe I can come back another time to the other verses you listed, Dan. My prayer is that the church will understand these things in the way Yahshua intended. How desperately we need to see things his way, not ours.
And in the end, it's not just a matter of correctly interpreting Greek texts (important though that undoubtedly is). The work of the Holy Spirit in our hearts is even more fundamental, only he can open the truth so that we see, only he can shine the light into the dark places, only he can lead us into all truth.