Whole Sort Of Genl Mish Mash
Part of the exercise of interpreting any literature is being aware of what is written before and/or after it. Context - The part of a text or statement that surrounds a particular word or passage and determines its meaning. Your reply suggests to me that you didn't read the chapters I mentioned and, therefore, failed to place John's opening words into their proper context. John's purpose in writing the first portion of his Gospel was not to establish the doctrine of the Trinity, but rather to introduce us to the eternal "Word," incarnate in the Person of Jesus Christ. When John is ready to write about the Person of the Holy Spirit, he does so. If you had read the chapters I mentioned above, you will see that the Apostle John did not neglect to mention the Holy Spirit (in considerable detail) in his Gospel:
John 15:26ff But when the Counselor comes, whom I shall send to you from the Father, even the Spirit of truth, who proceeds from the Father, he will bear witness to me; and you also are witnesses, because you have been with me from the beginning.
John 16:5 But now I am going to him who sent me; yet none of you asks me, 'Where are you going?' 6 But because I have said these things to you, sorrow has filled your hearts. 7 Nevertheless I tell you the truth: it is to your advantage that I go away, for if I do not go away, the Counselor will not come to you; but if I go, I will send him to you. 8 And when he comes, he will convince the world concerning sin and righteousness and judgment: 9 concerning sin, because they do not believe in me; 10 concerning righteousness, because I go to the Father, and you will see me no more; 11 concerning judgment, because the ruler of this world is judged. 12 "I have yet many things to say to you, but you cannot bear them now. 13 When the Spirit of truth comes, he will guide you into all the truth; for he will not speak on his own authority, but whatever he hears he will speak, and he will declare to you the things that are to come. 14 He will glorify me, for he will take what is mine and declare it to you. 15 All that the Father has is mine; therefore I said that he will take what is mine and declare it to you.
Why would an impersonal force or extension be called a Counselor? How could a mere extension "speak" or "declare"? This passage also indicates that this "Spirit of truth" is distinct from both the Father, from whom the Spirit proceeds, and the Son, by whom the Spirit is sent. This alone renders your "extension" argument untenable, unless you are suggesting that the Apostle John was mistaken. But then the burden would be yours to prove John's mistake.
Regarding the names issue, what was "YHWH's" name before he revealed it? Since the tetranomicon in the Hebrew didn't include vowels, how can we know that God's name, as He revealed it, isn't Yohwoh or Yuhwuh? What was Jesus's name before He was born?
Given the revealed nature of the Holy Spirit (i.e., His purpose is to "bear witness to [Jesus]" as the verse above suggests), theologians have often described The Holy Spirit as the "shy sovereign." The Father isn't accessible except by way of the Son, and the Holy Spirit bears witness to the Son, rather than to Himself. Christology isn't at the center of orthodox Christian theology by some accident, or by the whim of "mainstream Christianity, but by design, as it is borne out quite clearly in the New Testament writings.