Basically, this passage in Acts 20 mirrors what the Apostle Paul told the church leaders at Corinth in 1 Corinthians 9. It verifies that Paul supported himself and also those who were with him in an effort to not burden the church while allowing him to support the needy from his own earnings. Paul even quotes Jesus in this matter: "It is more blessed to give than receive."
The fact remains that in all of Paul's letters, including this third party account in Acts, there is no conclusive evidence that he ever received a salary from any church. And for that matter, there is no evidence in the entire New Testament of any follower of Jesus (Apostle, disciple or Jesus Himself) ever receiving a salary as a condition of their service in the ministry of the gospel.
"From Miletus he (Paul) sent to Ephesus and called to him the elders of the church. And when they had come to him, he said to them; “You yourselves know, from the first day that I set foot in Asia, how I was with you the whole time, serving the Lord with all humility and with tears and with trials which came upon me through the plots of the Jews; how I did not shrink from declaring to you anything that was profitable, and teaching you publicly and from house to house, solemnly testifying to both Jews and Greeks of repentance toward God and faith in our Lord Jesus Christ. And now, behold, bound by the Spirit, I am on my way to Jerusalem, not knowing what will happen to me there, except that the Holy Spirit solemnly testifies to me in every city, saying that bonds and afflictions await me. But
I do not consider my life of any account as dear to myself, so that I
may finish my course and the ministry which I received from the Lord
Jesus, to testify solemnly of the gospel of the grace of God. “And now, behold, I know that all of you, among whom I went about preaching the kingdom, will no longer see my face. Therefore, I testify to you this day that I am innocent of the blood of all men. For I did not shrink from declaring to you the whole purpose of God. Be
on guard for yourselves and for all the flock, among which the Holy
Spirit has made you overseers, to shepherd the church of God which He
purchased with His own blood. know that after my departure savage wolves will come in among you, not sparing the flock; and from among your own selves men will arise, speaking perverse things, to draw away the disciples after them. "Therefore be on the alert, remembering that night and day for a period of three years I did not cease to admonish each one with tears. And
now I commend you to God and to the word of His grace, which is able to
build you up and to give you the inheritance among all those who are
sanctified. I have coveted no one’s silver or gold or clothes. You yourselves know that these hands ministered to my own needs and to the men who were with me. In
everything I showed you that by working hard in this manner you must
help the weak and remember the words of the Lord Jesus, that He Himself
said, ‘It is more blessed to give than to receive.’” When he had said these things, he knelt down and prayed with them all. And they began to weep aloud and embraced Paul, and repeatedly kissed him, grieving
especially over the word which he had spoken, that they would not see
his face again. And they were accompanying him to the ship."
Proponents of paying pastors a salary and making ministry a professional livelihood must read "into" the scriptures their position, simply because there is no evidence anywhere in the scriptures to support their position.