Welcome to the board. Whole books are written on the several subjects contained in your OP; so do recall the limitations of this medium.
I will offer a modest stab at short (inadequate) replies to 1-7.
1. On the distinction between Z and C: the main difference is "where" the Supper, as the church celebrates it, is happening. The memorialist recognizes the church on earth is essentially doing a reenactment. The Reformed (by strict confessional and historical reckoning) recognizes the church's assembly is functionally on earth, but actually in heaven; and the meal where we sit is the same meal, with the same President surrounded by his disciples, as when it was inaugurated the night before his death. (for brevity's sake, I will pass on invoking the litany of Scripture texts used to explain and enact a theology of worship; perhaps start with Heb.12:22)
2. The Lutheran treatment of the Supper brings Christ "to earth" once again in/with/under the elements of bread and wine. The diagnostic Q sometimes posed is: what is in the mouth of the celebrant? If the answer is "bread alone," this is the Reformed understanding; if the answer is "Christ's actual body," this is the Lutheran understanding. The Reformed confess an actual partaking of "Christ's true body," but only after a spiritual manner. The Lutherans do not deny the spiritual manner of partaking, but they condemn those of us who deny also that the manner of partaking is carnal (fleshy). For the Reformed, Christ remains in heaven, and only those who really participate by faith enjoy communion through the Spirit; the heart is the hand and mouth of the soul. The Lutherans think Christ can only be despised in the Supper by unbelievers if they put their unholy hands actually upon him again, trampling him underfoot as it were. The Reformed recognize that spite to the sign of the truth is spite to the truth itself, much like trampling a nation's flag underfoot is no trivial offense to the nation the flag represents.
The Lutheran view is distinct from the Roman. The Roman (transubstantiation) philosophy is that the bread loses all of its "breadness," becoming Christ himself; hence by use of the "bread," participants receive the thing (Christ's body) itself, ex opere operato, by virtue of the work the work being done (especially that of the priest-celebrant). Lutherans, in addition to denying any change in the substance of the elements, also make a good deal more of the faith of the participants (less the virtue of the priest) for reception of sacramental blessing.
3. I believe Jesus' discourse in Jn.6 is a precursor to the institution of the Supper; the Gospel writer John has frontloaded the substance of Christ's teaching (that took place the night in which he was betrayed) by highlighting the anticipatory lessons in the miracles and sermons taking place long prior. John does not include Christ's institution of the Lord's Supper in the extended--longer than any of the other Gospels--treatment of the Upper Room discourses (chs.13-17). I don't need to impose the Supper itself on the earlier events to recognize allusions of what is yet to come. I'm not sure what sort of "false gospel" others may be guilty of; you'd need to offer some specific proposals you think are in error, then we might interact with them.
4. The WCF/3FU, historically situated, are meant to confirm the Reformed perspective, are by mistake made amenable to the memorialist view, and are at places worded explicitly to exclude peculiar Lutheran doctrine.
5. Generally, the memorialist view is default for mainstream evangelicalism. The modern Anabaptist view of the Supper is most likely cut from the same memorialist cloth; but one should not forget the radical origins of strictly Anabaptist theology, that included ideas like Christ's incarnational body was "celestial flesh" as opposed to sharing fully our human nature. Typical Baptists in America today are not affiliated with continental Anabaptist historical theology, but are memorialist; their theological heritage is quite mixed, with only Confessional types often coming close to or embracing a Reformed sacramental view.
6. "This is my body" meant when the sitting Lord said the words, and still means now exactly what he said in the original moment, that the sign he passed to the hands of his disciples held the reality (sacramentally) of spiritual union between Christ and his people. Through the very flesh and blood of Christ, we are bound up to him in a personal union, otherwise expressed through Paul as likened to the marriage union for example. In the death of Christ--the tearing of that flesh of his and the outpouring of that blood of his, being contained in the Person sat before the disciples--his disciples also die, their sins atoned for, but also rise again in his resurrection. Christ did not hand this disciple a piece of his elbow, another a portion of his liver. Christ's body sitting before the disciples did not extrude into the bread; none of its substance physically passed into the mouths and stomachs of the men sat beside him. Neither does his flesh now compose his presence with and within his people; but by ineffable operation of the Spirit we disciples commune even unto a bodily fellowship with the true flesh and blood of Christ by way of our hearts through the signal elements provided and the promise he associated with them. We sit over and over again in the same seats as the first disciples, receiving the same thing they received from the same hands, only with the additional benefit of Christ's finished work in hindsight; which more than makes up for whatever our eyes fail to see.
7. This question needs a great deal more space, and this reply is already overlong. I'll just say that in my estimation, the Table is far more massive than it looks, not only for all the saints on earth and in glory--OT and NT--who surround it; but the Table is crammed with all of the sacrifices and feasts and ceremonies contained across the previous administrations of the covenant of grace.
I hope this is a helpful start.