Additional details:
Half of the reported behavior is resolved.
There is no difference in behavior between "not detected" and "not connected" in the install process. The only variation occurs when the network port (one automatically detected and configured) gets an IP address - the DHCP graph finishes quicker. Otherwise, there is no indication (even momentarily) of success or failure in configuring a single supported network adapter in the absence of a second, detected adapter.
Changing this behavior is not terribly important IMHO.
The issue with the wifi adapter *may* be uncontrolled. I ran across an article online suggesting that the r8712u driver as it is found in the system (kernel driver?) *may* be in transition to a different software implementation. For the Live DVD to work one way and installation (from multiple media) would then be understandable. Since Linux generally needs to be VERY strong on implementing networking services, this part of this report should continue to be tracked.