In terms of the circles of confusion, you are so right. In fact I discount most dissertations on circle of confusion because it all depends on viewing distance (as you point out) and a good print (in my opinion) DRAWS the viewer IN to examine it closely.
Looks like I ran out of space to post prints, so check out the LF forum link above for the results. I need to think about it some before I decide the next step .
In case it wasn't clear in the first post, using a piece of glass over the paper and the enlarger as a light source produced too much artifact (ie dust and shadows from scratches) that my prints were a waste . Thus the need to sort things out and find a better way of doing it.
I don't WANT to be doing this testing , I'd rather make prints, but they are not turning out. The calculations in the initial post were just to get an idea of WHAT to test as the next step.
Anyway, check out the link above and see what you think.