Mattie,
Good thoughts. I as a street preacher strongly agree with your general line of thought. Much of what passes for "street preaching" these days has very little of God's Spirit involved in it. I suppose it's much like what we see in many heavily institutionalized churches, where operations can continue without the presence of Christ. Street preaching can often become simply another method in one's how-to-save-the-lost tool-box, along with the accompanying techniques.
However, as much as the leading of the Spirit is needed for one's open-air preaching and direction in ministry, let's be careful not to be so hyper-charismatic that we overlook the fact that in book of Acts that the Church which was highly driven by the Spirit still employed some "methods" in their ministry.
Take for example, Acts 16:6-10
They passed through the Phrygian and Galatian region, having been forbidden by the Holy Spirit to speak the word in Asia; 7 and after they came to Mysia, they were trying to go into Bithynia, and the Spirit of Jesus did not permit them; 8 and passing by Mysia, they came down to Troas. 9 A vision appeared to Paul in the night: a man of Macedonia was standing and appealing to him, and saying, “Come over to Macedonia and help us.” 10 When he had seen the vision, immediately we sought to go into Macedonia, concluding that God had called us to preach the gospel to them.
It's interesting to see how they were setting out to attempt to evangelize Asia-minor, and it was their hearts desire to do such, yet Christ simply would not let them do such. It seems He setup various obsticales to prevent them from going to Asia-Minor to preach the gospel. Eventually through revelationt Paul saw they should go to Macedonia to preach the gospel.
And Acts 16:13 continues...
And on the Sabbath day we went outside the gate to a riverside, where we were supposing that there would be a place of prayer; and we sat down and began speaking to the women who had assembled.
Paul, Timothy, Luke, and their apostolic team seemed to have an idea of some good "fishing holes" they liked to target people at. The were "supposing" that there was a place of prayer amongst the Jews at a certain location, and thought that'd be a good place to start preaching at.
It's interesting to note that Christ directed them to this town through a revelation, but once there they took up simply finding a good place to start their work. It's especially interesting to note that in Paul's dream he saw a Macedonian man asking him to come help out. Yet when Paul and his fellow apostles arrived there, they sought out a good place to preach at, and their first audience was a bunch of women (compare v 10, 13)!
We can see many such examples throughout the Old Testament, the Gospels, and book of Acts. When we read Paul's letters to the various churches, he regularly talks about his itinerary which seems to some degree up in the air, subject to possible future change. For example, in Romans 1 we read how he often wanted to come to Rome to partake of the fruit of the gospel there, but was unable to do such yet. Then in the close of Romans we read how he's intending to eventually go on to Spain.
So with all this said, while yes the Spirit-driven aspect of things is vital, and we must always seek the direction of God in our ministries, God will still bless the efforts and methods we set forth to do in His name so long as we diligently seek His blessing in that work.
