Very insightful. Thanks for posting your reflections. I hope you don't mind my sharing a few thoughts of my as I reflected on this.
For one, I find it interesting that you loop "death" as part of the enemies that might be subjected to Christ as his footstool. I think in general, even by the WTS, the specific enemies in reference are those still in heaven, meaning Satan and his rebel angels. They remain in heaven until they are cast out of heaven, but specifically down to the earth, which is called God's "footstool':
Isaiah 66:1 "...“The heavens are my throne, and the earth is my footstool."
So the concept of death being a primary reference to Christ's enemy would be secondary to the temporary time Christ's enemies are in heaven and would then be cast out down to the earth at which point they would become his footstool.
So in general, the date of the second coming would tend to date this event as Satan was not cast out of heaven until the time just before the second coming. Reflective of this is Revelation 12 where you see the birth of the messiah occurring just after Satan has been cast down to the earth.
Again, I think death, though called mankind's last enemy is conceptual and I don't think would be considered as part of this timetable, not as much as when Satan becomes the footstool of those in heaven. Furthermore, death is not destroyed and cast into the lake of fire until after the second resurrection which occurs after the millennium and thus after the second coming.
So in general, I tend to think more emphasis should be placed on Satan existing in heaven for the period while Christ is sitting (or standing) at the right hand of God. This brings up in what way would Christ no longer be at the right hand of God after Satan is cast ouf o hevean? Well, since Christ must return to the earth almost at the same time Satan is kicked out of heaven, it wouldn't seem he is literally at the right hand of God any more, since he, himself would also be in the earth, ruling admist his enemies.
So one interpretation of this is that Christ, standing or sitting at the right hand of God, representing Christ existing in heaven until the second coming, when Satan is cast down to the earth, would also end his sitting at God's right hand, since Christ himself would then leave heaven and return to the earth. So the concept of "until" is not contradicted here. That is, Christ remains in heaven "until" Satan leaves heaven, at which time he himself also leaves heaven and thus is no longer at the right hand of God. Even so, he rules as king on the earth "in the midst of his enemies" at this time, until Satan is cast into the abyss and the 1000-year reign occurs.
Psalm 110: "“Go subduing in the midst of your enemies.”
So what I'm now getting from this reference is that the chronology of Christ being at God's right hand, sitting or standing, is a reference to his waiting in heaven "until" Satan is cast down to the earth, becoming his footstool. But then Christ himself returns at this time, leaving God's side and then rules and goes subduing in the midst of his enemies, meaning in the midst of Satan and his demon followers and their earthly counterparts until Satan and the demons are cast into the abyss during the 1000 years. That is, it could not be said that Christ is still literally at the right hand of God once he returns to the earth to rule in the midst of his enemies who have become his "footstool" symbolically, since they are cast down to the earth and excluded from heaven. In the meantime, the ouster of Satan has created a place for those who would replace Satan and the demon angels. Christ spoke of creating a place in heaven for them but only after Satan has been cast out. So, again, you have a reference to Satan being cast out in connection with the second coming. What Christ does after his return is sends his angels out to gather and seal the elect into their heavenly seats, which is something that occurs after the second coming occurs.
As well, death is mankind's enemy that will one day be done away with after Judgment Day, which occurs after the millennium. But it can also be said in Christ's case in particular that he conquered death after his resurrection and thus death to Christ himself was no longer an enemy or threat to him personally. So, again, I would see the concept of specifically focussing on death as part of this reference a little stretched, particularly when the chronology of when Christ no longer is at the right hand of God is linked to his enemies becoming his "footstool" which can be a specific reference to his enemies being cast down to the earth since the earth is called God's footstool, specifically.
So in conclusion, I come away with the most generic reference here being that Christ is simply to remain in heaven until Satan leaves heaven, at which time he himself no longer dwells in heaven either. That is, Christ is at God's right hand, sitting or standing, and thus in heaven, until Satan is cast out of heaven and down to the earth. But that also ends Christ being in heaven at God's right hand as well, since he must return to the earth at this same time. In other words, this passage basically is recognizing that Christ will remain in heaven until Satan is cast out of heaven, at which time Christ will leave God's right hand and return to the earth. That is, Christ's stint at the right hand of God ends when Satan is cast out of heaven and down to the earth.
So if you deemphasize other than the chronology of Satan being cast down to the earth in reference to "sit at my right hand until..." then it means God is simply telling Christ that he will be up in heaven at God's right hand until Satan is cast down to the earth, at which time he will return to the earth. In other words, it is Jehovah telling Christ, to remain in heaven with him for the period of time prior to the second coming when Satan will be cast out of heaven. That is, Christ would not return to the earth but remain in heaven until Satan is cast out. But then after that, he himself would leave heaven and return to the earth.
OR... this is Jehovah telling Jesus, "You can stay up here with me at my right hand until we kick Satan out of heaven. Then, of course, you will return to the earth and rule admist your enemies for a while until Armageddon. At that time, we'll abyss Satan and you will remain in the earth to rule for 1000 years. Satan will be let loose for a short while and then be destroyed in the lake of fire. Then we will conduct Judgment Day where all the dead will return from the graves and be granted life or death. Then after the last wicked person is cast into the lake of fire and all other righteous ones are granted eternal life, then death itself will be destroyed, man's last enemy. Then after that, you and the bride class, who are also ruling with you on the earth, will be raptured up to heaven, all being changed in the twinkling of an eye, becoming glorious spirit beings."
Thanks, again, for reflecting on this. A secondary conclusion I also arrived at from reviewing this, is that "sitting" or "standing" at the right hand of God is not specific. It doesn't seem significant to the overall idea that he is simply up in heaven at this time, vs. being down on the earth. In the most generic sense, this is simply confirming Christ will be up in heaven at God's right hand until the second coming when after Satan is cast out, Christ himself will leave God's right hand and return to the earth.
