This thread actually got really interesting after I was afraid it was going to get stuck in the Argument Clinic. I agree with what Ken (N, not R) says about portraiture, by the way---that stuff is *hard* and I greatly admire people who can do it well. I sometimes hit it with people I'm personally close to, and there are few photographic results more satisfying.
Provenance is a complicated concept and can be important for several different reasons. I think a lot of people (especially at APUG, of course) feel like the wet darkroom creates a certain type of provenance that can't in principle be matched by a d*g*t*l workflow.
For the specific case of an in-camera b&w negative, I guess that's almost objectively true, in that the black stuff that forms the highlight areas comprises the VERY SAME silver atoms that were activated by actual photons reflected directly from the original subject at the moment of exposure; for a print, or for color film, there's an extra layer of indirection, so to speak, because there's another stage that derives some other form of the image from that original silver. On the other hand, a reasonable person could argue that it's not an important distinction, in that the image already is *not* the thing depicted and it doesn't matter how many additional processes you put it through, you already lost the identity of the thing when you allowed a bunch of reflected photons to represent the subject. I suppose that's an identity-based concept of provenance: it's understood as a kind of "chain of custody", which if broken represents a loss of authenticity. Ken---fair summary?
But you could also look at provenance in an accumulative way, which I think is more of a norm for hybrid photographers: Every stage of capture and processing leaves its "fingerprint" on the image in some way, and the identity of an image is sort of the sum of all those fingerprints. So that photo of my son that's in the hallway at home has some of the Sonnary goodness derived from the lens as part of its provenance, the association of my dad's old camera as another part (I took the shot in the first roll after the camera was handed down to me), whatever mystical signatures are imparted in E-6 processing, plus the digital provenance of the scan-and-print process, and so forth. The thinking here is that you can't remove provenance, you can only build on it.
Speaking just for myself, I find "provenance" to be quite an important concept, but as the years pass I see it more and more in that second way. Maybe this is a condition of middle age or maybe it's just me. Anyway, the whole subject has very little to do with how the final image looks, and I think Ken and I agree in feeling that its importance is independent of that---if you could produce the exact same image by two different routes, it would still matter (to us) which route you took.
There's a short story about this subject by Jorge Luis Borges: I believe it's called "Pierre Menard, Author Of The _Quixote_". As usual, I think Borges has anticipated all of our positions in this discussion and had more thoughts about them than any of us have...