Generally speaking the settings I change are:
Disable onboard audio
Disable onboard Video
((If it has it and using hardware for these))
I also always set 1st boot device as CD Drive (this way it checks if your trying to boot from a disk before starting Windows)
2nd Boot device HD
SATA Mode AHCI
Also, if I were you, after the flash and setting to Optimized defaults, let it boot back to Bios and then power down completely.
Then start up and make the changes you need too.
This way, the MOBO actually restarts. Otherwise it just makes changes and keeps running
Likely not needed, but the way I prefer to do it.