I agree with your point that this list is not for personal attacks.
About flexible or rigid diaphragms.....
The best way to model diaphragm is "partially rigid connection" that
allows structures to be modeled into any possibilities. Each connection
force can be modeled from perfect rigid to totally free. If a diaphragm
is designed, for example, for vertical forces only, only the vertical
forces should transmit to the diaphragm. In this situation, simply
reduce the connector strength to a very small value (i.e. 0.0001% of
perfect rigidity) for unwanted force components, and keep a high
strength (i.e., 95% of perfect rigidity) for the vertical force. Then,
the diaphragm has vertical force only. The partially rigid analysis
outputs the "connector loads" and "connector stiffness". The "connector
load and stiffness" are the reference to design connections. The
distribution of internal forces and moments depend on the connection
stiffness. The "connector load and stiffness" may ensure exact response,
i.e., the diaphragm has vertical force only.
A connection design must check "adequate rigidity", connector stiffness,
(UBC has the requirement). "Partially rigid connection" is a new
technique. Any interest to have more discussions?