The key part of what you wrote above that really is pertinent to my point is "Now obviously no right is absolute", and that is exactly how the SCOTUS has not only viewed the 2nd but also all other amendments. It does not state nor even imply "that a right already exists for the people (not the military or militias) to keep and bear arms...", and we know this not only from the wording but also how that decision was largely rationalized by the FF. It's been only the Heller Decision that has gone more in your direction, but that's not been the standard throughout our history, and even Heller does not fully open the door for an absolutist position of anyone and everyone having a weapon of their choice.
Therefore, with that in mind, along with the fact that conditions can and often have changed, one simply cannot logically claim that the 2nd is some sort of absolute right for every citizen to keep and bear arms. The situation in terms of where we were over 200 years ago and the types of weapons now available differ substantially, therefore "flexibility, but without losing sight of original intent" is the key here, and the "original intent" had mostly "A well-regulated militia..." in mind.
Either way, we actually are not as far apart as it may seem, or so it appears. It's sort of a glass half-full/half-empty kind of thingy, at least as I see it.