I'm sorry you didn't get your article published, but I agree with much of what you write regarding the Spirit of God. The work of the Holy Spirit in us today is an area that much of the Christadelphian body resist, just as the Pharisees of Stephen's day also always resisted the Spirit of God, because the active working of God's Spirit would mean change that threatened all the human traditions that we find. For taking these verses as they are written and experiencing the presence of God I myself was disfellowshipped. Yet they do mean exactly what you say.
A lot of explanations other than what they say have been presented to me. For instance it has been suggested to me that they only applied to the first century Christians. It is suggested we now only get the action of God's working of His Spirit today through the medium of the Bible. Others suggest that the words really mean the 'spirit-word' a phrase which is to be found nowhere in the Bible. Yet it is hard to see how the direct working of God could easily be replaced by the indirect effect of our reading the Bible and our interpretations of it within the limitation of words.
The issue of freewill is a little bit more complex. If everyone has freewill, then it means a lot of Christadelphians are willfully denying God in their lives by resisting God's Spirit. In my experience that is not so. Many simply do not understand. The idea of God working on our hearts is foolishness to them. they cannot understand how God could work in them and because they have no faith they cannot believe first and understand second through experience. So they are trying to understand something that we learn from within in our hearts with their minds. They are trying to understand too much first without taking the words exactly as they read.
In practice we do not have freewill, yet it is also true that we aren't automatons either. We have a will and we are conscious of having a will and of making choices. Yet we are also under the influence of certain things which cloud our ability to have fullness of will. We are influenced by our religious upbringings and traditions for instance. Certain people can have a bearing on our opinions. Our human nature creates a 'natural thinking' which affects us and the world we live in places pressures on us which affects our thinking and willingness to believe certain things. We are affected by what nutrition we take in, our state of fitness and health and much more. We certainly need strength from above to begin to overcome and challenge all the elements which resist God and his message.
From an Old Testament perspective we most certainly do have freewill, but from a New Testament perspective we do not. That is because the Old Testament was a shadow to bring people to Christ, whereas in the New Testament we find the reality of Christ and his Spirit spelt out more clearly. Since the Christadelphians tend to focus on the Old Testament they frequently miss the relevance of Christ and replace it with a focus on empirical doctrines which do not save. The Spirit of God is very much about Christ and how he and the Father now dwell in us. The Spirit is 'God in us' and 'Christ in us' and the 'Spirit in us' and the Bible says in Corinthians that 'no one can call Jesus Lord except through the Holy Spirit'. We have to have a real relationship with God and not simply one with the Bible that he inspired people to write. It is not the Bible which saves us, but knowing the risen Christ and whilst we can learn about Christ from reading the Bible we have to come to 'know Him' something which is very different.
It is very difficult to get through to many Christadelphians, because they are so entrenched in the idea that they and they alone have the correct interpretation of scripture and no one else can teach them anything. I believe it is this arrogance that has to be overcome before people will understand the issues that you are talking about. In our natural minds we are spiritually blind. None of us can come to God on the basis of our strength or intelligence or ability to correctly interpret scripture and unless we feel God's drawing we cannot come to him, because we naturally think we can see when we cannot, we can hear when we cannot. God has put us all in the same position of helplessness and yet the BASF doesn't recognise this and claims that people who are idiots cannot be saved. That's the inevitable consequence of having a form of religion where salvation is dependent upon your intellectual understanding. Yet in scripture the mentally ill often understood more than the most intelligent leaders of the Jews, because its not about our intellect, but about giving up the heart and to many Christadelphians there is no difference between the two. In essence you are changed by how much you read the Bible and understand it, not by how much you have given up the heart.
It all goes also against the tenor of the scripture, because in the Bible we find it is the poor and weak and despised of this world who are most likely to have faith. That's because they have least reason to trust in the flesh. It has let them down too many times. However they are the ones least likely to have that access to the bible, that training in reasoning techniques, that heightened ability to balance the text. A book-based method is also contrary to what we read in the acts of the apostles and it would have frustrated the fast spread of the gospels. They themselves talked of being 'led by the Spirit'. Yes they had the Old Testament scriptures (the New was not yet written) and they used it to reason with the Jews and see the progression of God's purpose, but primarily it was an oral message spread with a power don't see today in the main. I think it has less to do with the Spirit only being there to give us the New Testament and more to do with the body of Christ not having the necessary faith and wisdom which comes from experience and which we are still learning.
If the spirit comes purely through the medium of the Bible, then a body of people as well read and studious as the Christadelphians should by now have the perfect faith, yet what we see in practice is often a set of traditions and an adherence to doctrine and statements of faith which is stultifying. Something is missing and that missing something is power and spirit and life and every time someone realises that they will be more and more ready to be drawn to the leading of God's Spirit. Whilst they stand in the power of their intellect and interpretations and traditions they aren't ready to turn to God with all the heart. They have no need for Him. They've got the Bible and they can read and they are happy to believe that if they know the Bible enough they have God. That isn't necessarily the case. I could read everything about you and I would know all about you, but I wouldn't know you and more importantly you wouldn't know me. You might be happy to have a relationship with me simply by reading all about me. To me though that wouldn't be a relationship and its not what Son meant by him and his Son making their home with us. It's a little bit more personal and intimate than that.
Without the Spirit of God we are really serving God through the fleshly mind. We may have learn through mental discipline to keep the body physically in check, but it's an arduous and unrelenting way to try to serve God. You won't keep up your mental progress unless you read the Bible enough for instance. You have to be sure that you have the right interpretations and read the right translation of the Bible and balance it rightly. It is not like a relationship with God where you can feel your closeness and distance from him. You will always feel as if you aren't good enough and feel you must always read more and try harder. If you should have a mental breakdown you are in real difficulties, because it's only with a strong mind that your method will work. If you cannot absorb the Bible or get strength from its ideas you are now in a very helpless situation. In fact this constant pressure to move forward through knowledge could break you mentally, because without the Spirit of God we are under law and the object of law is to get you to give up and have faith. To deny the conclusion as an organisation is to make it very difficult for people to come to the real heart knowledge of God which matters.
God will not take this resistance of his Spirit lightly I don't believe. I hope he does find a way to draw the Christadelphians forward and it may happen as the world closes in as it is doing and we find we need more than words and interpretations and find we need God's real presence.
Much love and blessings in Jesus, your brother,