Your original statement was "This you do not see in Acts. What you do see is open air preaching and direct witnessing with strangers." You were pretty adamant that these examples don't happen in Acts. Now you've had to walk yourself back and say they're "rare."
I don't believe they're as rare as you'd like to believe. I don't think you're taking into account culture. The middle east is big about family and how to treat guests. So while there are examples of witnessing and then quickly leaving (Philip and the Ethiopian come to mind), the evangelism done in Acts 2 took place over a period of time. It's most likely that they held dinners together; and they worshiped together; and they demonstrated relationship and commitment to one another. Look at Acts 5:12-16; a clear indication that they were there for a period of time. Acts 5:42; another indication that they were there for more of a time period than just evangelizing and direct witnessing. Look at Acts 19:8; it says Paul was there for several months. Surely he made some relationships in that time?
Sorry, friend, but what you've accepted as truth about open air preaching and direct witnessing from the book of Acts, doesn't hold up to what scripture actually says. I'm not speaking against open-air preaching/direct witnessing; I'm speaking against those methods allegedly being a primary means of spreading the gospel, or somehow being of more importance than other methods; or somehow making you a better evangelist than others. And no, don't bother trying to say that you weren't trying to imply that they were a primary means or more important than other methods; you don't have to defend this. Keep doing what you're doing, because it's your gift, and it's what YOU can do. But you don't need to continually try to justify it, and end up making erroneous statements like "This you do not see in Acts." The only way you need to justify it is by saying, "this is what God has called me to do." Period. End of story.