Hi there,
with your motherboard and BIOS revisions you can safely flash back to the FB in the same way you would update the BIOS.
Things to remember are:
Use QFlash as this is probably the easiest and safest method.
Before you actually flash the BIOS, load Optimised Defaults and let the system restart with default settings. You don't have to go into the OS you can go straight back into the BIOS.
Update the BIOS or flash back to an earlier version using QFlash.
After flashing the system will restart, go into BIOS and load Optimised defaults again, save and exit.
When the system restarts you can either go back into BIOS and tweak it or let the system load the OS.
Points to consider:
If you are running a RAID Array, BIOS flashing will reset everything so you will lose the Array and need to rebuild it.
Updating or flashing back the BIOS can cause Windows OS to think you have a new PC. This can sometimes cause Windows to request reactivation.
Flashing the BIOS either up or down can cause problems. The old adage of: "If it ain't broke, don't fix it!" must seriously be considered. Ask yourself Why you are planning on flashing the BIOS and is it really necessary?
Sorry for the lecture but, we see so many posts where users have flashed their BIOS and bricked their motherboard that it is best if you make an informed decision on BIOS flashing.
If you have any questions then it is best to ask them before you proceed with BIOS flashing rather than later, if things have gone wrong.
Good luck.