I certainly agree with most of what you are saying! But I find the 144,000 are literal Jews at the end of time for a specific end time mission.This is opinion without biblical proof texts. While I agree that Rev & Dan speak of both things of heaven and earth, I don't believe the 144,000 should be interpreted as being on the earth since they are located in the heavenly realm of God after they have physically died. That is where only as spirit we reside with Christ and an innumerable company of angels. We know this because the text tells us they are on Mount Sion with the slain Lamb. To read this as Mt Zion of the earth would make no sense. They are a spiritual body alive with Christ in heaven, because after our body dies, our spirit returns to the Father just as the spirit of Christ ascended to heaven when His body breathed its last. (Ecc 12:7 & Lu 23:46)
Spiritually, not physically we (our spirit/soul) belong to Christ eternally when we are born again. Even before we die our spirit has been made perfect through the Spirit of Christ within us, that our spirit shall never die. That's why as spiritual body we ascend to heaven, (1Cor 15:44-50) the heavenly Jerusalem with the angels of God there. It is only our spirit that can ascend to heaven when our body dies because our body shall not be resurrected immortal and incorruptible until the hour coming when the last trumpet sounds. (Jo 5:28-29 & Rev 10:5-7)
Hebrews 12:22-24 (KJV) But ye are come unto mount Sion, and unto the city of the living God, the heavenly Jerusalem, and to an innumerable company of angels, To the general assembly and church of the firstborn, which are written in heaven, and to God the Judge of all, and to the spirits of just men made perfect, And to Jesus the mediator of the new covenant, and to the blood of sprinkling, that speaketh better things than that of Abel.
The New Jerusalem is where, as spiritual body of Christ, we saints shall spiritually dwell until the first heaven and earth passes away. Then we, the holy city New Jerusalem shall come down to the new heaven and new earth as a bride adorned for her husband. After physical death none who are with Christ shall be resurrected to life again to inhabit this earth. (Rev 21:1-5) For this reason the 144,000 are seen in heaven and not on Mt Zion of this earth.
But God is also giving us a vision through John of what will be … the 144,000 and the multitude… the 24 elders, etc., are future scenes of God’s victory and after everything is fulfilled. Mt. Zion reference lets us know this is a vision in heaven , not on earth.
Thanks.