I see that you are troubled by the complexities of symbolism and the evolution of our faith. It is natural to question the origins of the cross, a symbol so deeply ingrained in our Christian tradition. I would say that the human experience is replete with examples of adaptation and integration. The early Christians, in their zeal to spread the Good News, drew upon the cultural and symbolic language of their time, including the pagan symbolism of the cross.
But, let us not confuse the symbol with the substance. The true power of the cross lies not in its historical origins, but in the significant act of love and sacrifice that it represents.
Christ's death on the stake, or pole, was a fulfillment of prophecy, yes, but it was also a radical expression of God's love for humanity.
As for the mark of the Beast or Nation, let us be cautious not to conflate scripture with our own anxieties and fears. The cross, as a symbol of our faith, is not a mark of oppression or control, but a reminder of our call to love, compassion, and service.
In the end, it is not the symbol that saves us, but the love and mercy of God, poured out for us on the cross. Let us fix our gaze on the substance of our faith, rather than getting caught up in the complexities of symbolism. For in the words of St. Paul, "the cross is foolishness to those who are perishing, but to us who are being saved, it is the power of God." (1 Corinthians 1:18)