I was very much ready to buy another motherboard, ketchup

This was especially true because the return window for my Micro Center was closing. I ended up swapping the motherboard and the problem is gone. I'm now using the MSI Z97 Gaming 5. Money out of pocket: $0! Score!
All the hardware for video was the same (same monitors, same card). I guess there was some sort of incompatibility somewhere. I had this issue a few years ago when the hard drive of all things caused blue screens with the chipset I had been using beforehand (and that time, I swapped out my motherboard to no avail

). See
this if you are curious.
One last question that has no relationship whatsoever to the thread:
Why does the first DIMM for RAM *have* to be on top of the motherboard? I can't get my Zalman heatsink installed because neither mobo POSTs...