Openness == earlier commercial/industrial revolution is an overdone clique with no basis in reality. It should be noted that none of the more open states such as the Ottomans or the Indian princely states were actually able to industrialize despite being quite open with the west. Even western states like Spain failed to industrialize despite being a "normal" European country.
Every society reacted to "modernization" differently. But you're right. "Openness" in isolation is not a guarantee of early adoption of industrialization.
The Tokaguwa Shogunate did three things that permitted the Japanese to be the only industrializing non-European country before the 1950s:
2) Keeping Japan out of any stupid foreign adventures like Hideyoshi's invasion of Korea. Those tend to involve a massive amount of silver being spent or exported for little/no gain. In a monetary system based on precious metals this result in massive monetary contraction and therefore overall economic activity. Also I would argue that even a -successful- Japanese acquisition of foreign territory would be of little benefit to industrialization for the most part.
I don't think there is the evidence that Nobunaga would have indulged in foreign adventures, or to the same degree as Hideyoshi did. It is interesting that Oda's 2 immediate successors, both close to him, would take such different roads in this matter. Perhaps without the lessons learned from Hideyoshi's adventures, Ieyasu might have gone down the same path.
All in all, I agree with most of what you've laid out (a very comprehensive post)-- that these were the signal Tokaguwa achievements -- but they honestly seem very related to Nobunaga's incipient reforms. If anything, Tokaguwa (apart from Ieyasu's and his successors aversion to foreign influences) was in many ways, very much the true successor to Nobunaga's dreams. Hideyoshi, despite sharing the common aims of unification and centralization, tried it in his own ultimately self-destructive way.
I believe that the Tokaguwa did have the effect of freezing the social classes for the benefit of social control. Evidence would suggest that Oda would have been more liberal in this regard. An argument could be made for increased social mobility and more liberal attitudes to foreign influences might in time had led to greater economic liberalization and growth, as well as a quicker path to technological innovation.
We have the benefit of looking back to the OTL sum of achievements of the Tokagwa legacy. Nobunaga's, in many respects, were still-born, except for the dreams that motivated his OTL successors. We don't know what his hereditary successors (if any) would have done. Hence, he becomes AH fodder. One of the big "What Ifs?" of Japanese pre-modern history.
So, I suggest the possibility, in effect, of a somewhat less insular "Tokaguwa", with a different name, achieving much the same position for Japan, perhaps a little earlier. No more a wild surmise than for the PODs of most TLs on this Site.