Who can comprehend the nature of God? Of course, only God Himself...
Who can comprehend the nature of God? Of course, only God Himself. But what is essentially important for our salvation, He reveals to us. Therefore, the Church has always tried to be precise in comprehending this Revelation, so it is necessary to clearly envision what is important for our coming to God.
The idea of the created nature of Jesus Christ was first expressed by the Alexandrian priest Arius at the beginning of the 4th century AD. The Church quite unanimously rejected this opinion as erroneous, because if it was not God who shared our life and our death with us, then there is no salvation from sin and death for us. Likewise, if the Holy Spirit is a faceless force (a sort of semolina porridge, God forgive me), then communion with a Personal God is impossible for us. In this case, again, there is no salvation, because the entire biblical faith collapses. After all, the Holy Spirit is precisely the One Who pours life into our hearts, and not in some Hellenistic "afterlife existence" (which is a non-biblical idea), but here and now. Thus, the Church believes that Jesus is the God-Man, consubstantial with the Father in His Divinity and consubstantial with us in His humanity, and the Holy Spirit is a Person, God, whom we worship together with the Father and the Son.
The arguments you write about do not seem convincing. Of course, Jesus prays—how else can a man (and God incarnate in a man as well) communicate with the Father? The manner of communion between the Father, the Son, and the Spirit in the Trinity is incomprehensible to us; but the God-Man Jesus Christ is humbled for our sake to such an extent that He also shares our manner of communion with the Father. As for the worship of Jesus Christ, the Holy Scripture says that it is precisely the belief that He is Lord that gives a person salvation. The Apostle Paul in his Epistles to the Romans ( 10:9), to the Philippians ( 2:6-11), and to the Colossians says that the will of God regarding our salvation is that we worship God in Jesus Christ, since "in Him dwells all the fullness of the Godhead bodily" ( 2:9). Obviously, the opinion of Arius regarding the created nature of the Son of God radically contradicts these last words of the apostle.
The Holy Spirit, of course, can act in every person, and in many people at once, for He is Almighty! And the "divided tongues, as of fire" are only visible signs of His coming, not He Himself. Ultimately, I reply to letters from many people—does my personality thereby divide into separate pieces of paper?
It is truly important for us to know and accept what is expressed in the dogmatic teaching of the seven Ecumenical Councils, including the concept of the Trinity, first explicitly formulated by St. Theophilus of Antioch in the second half of the 2nd century. The Triunity of God means for us that He a) is not like us; b) transcends us and our understanding; c) has life in Himself; d) gives us the opportunity to share with Him the fullness of His life. This is in brief, of course. The Church's teaching on the Triune God is profound and significant enough to become acquainted with it through the Bible itself and specialized sources.
Everyone, of course, is free to choose their own confession. But it is important for Christians to remember that every dogmatic assertion has consequences in practical spiritual life, and these consequences must be seen and evaluated by their fruits.