Building the CustoMac Pro for HD Video Editing

Ok I managed to install everything, now I have some problems to solve but I would say that 80% work.

This is the final configuration:

	CPU	Core i7-4770K 3.5Ghz 4 Cores / 8 Threads Turbo Unlocked for Overclocking 8MB L3 Cache 84W Max TDP
	Mother Board	Gigabyte Z87X-OC Socket 1150 Z87 Express DDR3 S-ATA 600 ATX Haswell GiGABYTE UEFI Dual BIOS
	Graphics Card	ASUS GeForce GTX 770 (2GB) 2048MB GDDR5 256bit Base Clock: 1046 MHz Boost Clock: 1085 MHz Memory Clock: 7010 MHz CUDA Cores: 1536
	Memory	Corsair 16GB DDR3 1600Mhz (2x8GB)
	Hdd	Western Digital 3,5' Caviar Red 1 TB
	SSD	SanDisk SSD Ultra Plus 256 GB Black Hard Disk Flash SATA Revision 3.0 6Gb/s
	Power Suply	Corsair CX Series™ Modular cX750M ATX Power Supply — 750 Watt 80 PLUS® Bronze Certified Modular PSU

	Case	Vengeance® C70 Mid Tower Gaming Case — Arctic White Windowed
	CPU Cooler	Hydro Series™ H100i Extreme Performance CPU Cooler

Video Flash: the screen flash for no reason, for a second goes on a black screen then reappears, this for several times and then nothing for a few minutes, then resumes. I thought it was a problem with the screen saver but also eliminating the screensaver the problem persists.
It seems that using the graphics card mather board does not, bat flickers (I hope it translates well)
SOLVED:
I've change wire, it's was broken!!


Audio: sound card will not work, nor by the HDMI
RESOLVED:
In MultiBeast chose: Drivers > Audio > Realtek ALCxxx > Without DSDT > ALC892
In Mavericks: System Preferences > Sound > Output > Internal Speakers (Integrated)

USB: Anytime when inserting a USB stick or an external hard pc crashes.
RESOLVED:
In BIOS setting: Peripherals > DEVICE Config > legacy USB Support => DISABLE

These are the settings in MultiBeast:
If they can serve the settings of the Bios I can post screenshots, just tell me what might be useful.
Obviously I'm not very experienced then may be I have the wrong settings in the bios and UniBeast, someone might post the settings for the various parts so that I can try to fix the errors?

Dual boot: I have to figure out how you set up dual boot.
What is the exact procedure to install in dualboot other operating sitemi? Where can I find a guide?