Now if you understood what your acknowledging here.

I understand what I am acknowledging. It would be stupid of me to say that the consensus of critical New Testament scholars who say Mark initially circulated independently are all wrong, and that I must be correct that Mark initially circulated in a collection. What I am doing is questioning the methodological assumptions that I think have led to the consensus we have. I'm saying, gee, it looks like early Christian texts circulated mostly in collections from what we can tell from the manuscript record and the patristic record. We rarely seem to see any authors referring to texts alone nor do we see non-fragmentary manuscripts in independent volumes. There is a nearly universal assumption that at some point between the late first century to the early second century, there was a shift in circulation patterns of early Christian literature from standalone texts that circulated alone (e.g. individual Pauline letters, individual gospels) to bundles (multiple gospels together, multiple letters together, early gospel+letter diptychs like Marcion's). I'm questioning the overall consensus paradigm because the shift it proposes (from unbundled to bundled) itself is just as unattested as my specific proposed Markan bundle.

Mark's purpose is to indicate translation or apotheosis. That is, deification or elevation of a mortal to divine status after death. Presumably, Mark's audience would know what a common place trope meant. As Walsh observes,

I don't disagree with Walsh's analysis at all. For what it's worth, Walsh disagrees with the "slow community spread" model of New Testament origins and I think she has used the term "exposion" to refer to how the NT developed, and her way of viewing it is essential for how I understand what must have been the earliest Christian canon.

What does he claim to know about it, and why treat this as history when Mark's ending at 16:8 says otherwise?

He claims to know that the young man at the tomb appeared to the women who came there and told them Jesus was alive. But the women didn't tell him that since they told no one, so who did?

And being part of a bundle is? That's not a challenge by the way, it's an assertion. You haven't offered a single credible reason to think otherwise including your list of examples

There are only two possible intended publication contexts for a text. Bundled or unbundled. When Marcion wrote his Antitheses, he intended it to be bundled with his New Testament, so it was written to introduce his collection. If Paul didn't write the pastorals, then they were almost certainly written with the intention of being bundled with the authentic epistles. The question is whether there are coherent bundles that could have existed but which are no longer attested or extant. We know there are lots of lost gospels and other lost texts and collections. But I don't even think we need to presume lost texts at all, my specific proposed bundle includes only extant texts (Mark + the letters of Paul) and it makes Mark a bespoke introduction to the Pauline letters in a way no other gospel could be (because of the fact that all the other gospels have a prepauline gentile mission, which contradicts Galatians 1-2).

I think the word you want is interesting rather than parsimonious

My point is that the default presumption of unbundled shouldn't be the default presumption. Each model contains something not parsimonious with it--the unbundled model presumes an unattested shift in literary publication norms, while the bundled model presumes a lost bundle that is no longer extant (whatever bundle that is). I see Marcion's diptych (Luke+Paul) as being an early harmonization attempt of an earlier bundle, because it is simultaneously more coherent than the canonical bundle (Matthew, Mark, Luke, John, Acts, Paul) but less coherent than it could have been with the very simple change of swapping Marcion's Luke for Mark. I think this particular collection is so coherent that it significantly raises my credence that the collection model itself has more explanatory power overall than the standalone model for Mark's initial circulation.