Thank you all for the replies. VERY frustrating trying to get Win7 installed on my NUC - it's even more frustrating that I seem to be one of the few owners having problems.
I did manage to get a Win7 disk (the same SSD I started with two weeks ago) to boot into the OS yesterday. Unfortunately, the system was still hosed somehow.
Any action I performed - double clicking on a folder to open it, right clicking on the desktop to change display settings, etc - would takes minutes to complete. I thought maybe I needed to do the 146 updates available right now for Win7 SP1 64 bit but that didn't correct the problem(s). Another 7 hours wasted.
I also tried a different mouse and keyboard, thinking maybe my Logitech wireless mouse/keyboard were to blame - no change.
Tried disabling all unnecessary items - wireless/Bluetooth card, onboard lan, etc - no change.
I even tried booting up in safe mode to see if there was a driver or other software problem - no change.
Finally gave up today and initiated an RMA for my NUC.
Hopefully the replacement will function correctly.