You have your hypothesis and I have mine. We will only be able to determine which is correct with the benefit of hindsight. Like I said upthread, the nice thing is that these hypotheses are at least partly testable. If your theory is correct (that the market will tolerate a limit to the left of Q*) then that would have the affect of pushing aggregate fees above the aggregate cost of production for block space. If the total miner fees collected over a six month period in the future were, for example, twice the total block rewards lost due to orphaning, then I think I would agree that your theory is correct.
Time will tell.
My hypothesis is supported by current observations of the network dynamics.
Currently, aggregate fees are less than aggregate orphan costs.
I agree that miner's will optimize for profit. That's the working premise of my fee market paper.
The market-governance hypothesis is falsifiable. However, currently the empirical data does not refute it.
Regarding the transaction fee market, empirical evidence already shows that on average bigger blocks contain more fees. Additional fees are necessary to offset the larger block's increased chance of orphaning. Approximately 1% of blocks are orphaned, resulting in a loss to the miner. This is what creates a fee market as described in this talk at Scaling Bitcoin.