I probably agree with you on most points as its probably more accurate then me rambling off the top of my head. By I do know back in 2004, Honda did have a Pilot prototype being tested for the ridgeline that had a V8. It was a spy shot done by Brenda Priddy (I beleive thats her name.)
It was speculated the new RL would release with the V6, and during its mid-cycle update get this V8. But after that, I've heard nothing about it.
As for keeping sales up... I can agree you always want volume... But sometimes volume isn't all thats there. Porsche is a prime example of how the company controls manufacturing resources to keep volume in line with demand. Honda needs specilaty teams to handle its specialty cars. The S2000 needs to be unmiata like, and more 350z/G37/GT-R... Hell Toyota is even doing it with the speculated Supra in V6/V8/V6 Hybrid forms.
The NSX needed an update, not a platform change. They should introduce a new designation, not NSX for that.
And right now, the Audi R8 is what will most likely replace my NSX if they new ones aren't what they were suppose to be.