As a matter of fact I can't think of a single instance where a New Testament prophet was not involved and known among the local assembly of believers. I would go so far as to suggest that it might be true that there was no such thing as one who was not involved in a local assembly. All new testament prophets had their ministry in a local church. No one can call themselves a New Testament prophet today unless the local church calls them that and knows them very well. That is the image I get from Acts.
The crux of the 'war' between people who are genuinely apostolic and prophetic vs. those who are pastoral, evangelical, teachers, and those who follow them is that the latter group is often content to remain in the milk of the Word while the former insist on moving on to the bread and meat. As a result, both sides tend to disagree.
1.)
"I write to you, little children, because you have known the Father. I have written to you, fathers, because you have known Him who is from the beginning. I have written to you, young men, because you are strong, and the word of God abides in you, and you have overcome the wicked one" (1John 2:12-14).
2.)
"I, brethren, could not speak to you as to spiritual people but as to carnal, as to babes in Christ. I fed you with milk and not with solid food; for until now you were not able to receive it, and even now you are still not able; or you are still carnal. For where there are envy, strife, and divisions among you, are you not carnal and behaving like mere men" (1Corinthians 3:1-3).
3.)
"Though by this time you ought to be teachers, you need someone to teach you again the first principles of the oracles of God; and you have come to need milk and not solid food. For everyone who partakes only of milk is unskilled in the word of righteousness, for he is a babe. But solid food belongs to those who are of full age, that is, those who by reason of use have their senses exercised to discern both good and evil" (Hebrews 5:12-14).
In 1Jn. 2, John exposes the three levels of spiritual growth: little children, young men, and fathers. The structure of modern church is pastoral and is content to corral and baby the sheep and make sure they are 'safe' and comfortable. On the other hand, apostolic and prophetic people want the churches to move on past infancy and ford into the depths of God, the adventurous and dangerous places of knowing Him here and now and not waiting till Heaven.
You said that one must be intimately involved in a 'church' before speaking to (or even about) that church. This isn't biblically true nor is it practical. We don't have to be friends with the weatherman before listening to his forecast or befriend our school teachers before learning from them. They are paid by 'someone else' to do what they do. You also said a person must have a heart for a church before admonishing or rebuking the church. The implication is that we can see on the surface when a person has a heart for a church. Yet, the prophets in the Bible were often rejected. The OT prophets had harsh messages and though being God's people themselves, their brethren accused them of not having a heart for God's people. The same happened to Jesus.
God looks on the heart; our part is not to judge people by their outward appearances (afterall, I was in a church where satanists were exposed who, up till that time, were accepted and trusted by the entire congregation because they seemed good on the outside). Our part is to listen to what everyone says (including the pastors we trust) and then look for ourselves whether what they're saying is of/from God, whether the Bible supports it, and whether the Holy Spirit (and sometimes just our conscience) agrees.
There are varying degrees of spiritual death. Jesus telling me the churches are dead doesn't mean they can't be resurrected. Afterall, the valley of dry bones. But infants who are enthralled by marbles sooner or later grow up and find out about diamonds. When diamonds come into view, then marbles no longer exist to a person. God has been calling christians higher for 2,000 years (this is why we've had revivals, reforms, and awakenings); but most christians don't want to move forward. Like Israel, they prefer to receive God's blessings in the desert where life is easy than to cross the Jordan and get far more blessings... with the catch being that they must fight, struggle,
and GROW. The genuine apostolic and prophetic want people to start growing up. Most pastors and christians in the West don't want to grow up. So there's that constant 'struggle' between those two camps.
But now, don't adhere to rules and cliches that haven't been proven true. Saying things like "All new testament prophets had their ministry in a local church" is really a way of setting up boundaries to protect your comfort rather than a statement of the truth. As humans, we'd like to choose our friends, our enemies, who can influence our lives, and who can't. But God doesn't respect all our boundaries and does send people we don't know or have never seen to speak to or minister His will to us. If we could only receive from those we 'know', then 99% of us who have 'received' the gospel are disqualified since we didn't [yet] know the person who told us the good news. Don't set up boundaries that God hasn't set up. Out of love and concern, God will eventually crash through those boundaries. That's the bad news. And most of the time He'll do His crashing with prophetic and apostolic people. That's the even worse news.
The person who is open to God is open to Him no matter how He manifests. The Jews rejected God in Jesus because of the manifestation, stating all the reasons Jesus couldn't be the Messiah just as many state today why God can't speak to or reach out to them in this way or through that person. Jesus said in His defense and in the defense of all who He would later send-- from the apostles of that era all the way down to all who Jesus will send until He returns,
"My doctrine is not Mine but His who sent Me. If anyone wills to do His will, he shall know concerning the doctrine, whether it is from God or whether I speak on My own authority" (John 7:16-17). So, the rules are not so much "You must be in relationship with this or that church or ministry or person before you can speak into their lives" but rather that
there's a responsibility on the hearers and audience to test the message and the messenger and find out for themselves whether or not they are from God. This puts the responsibility on everyone and not just on the messenger.