Clover or Chimera?
For Chimera, you have to install FakeSMC plugins with multibeast as well, see screenshot.
For clover, install http://sourceforge.net/projects/hwsensors/ and move the FakeSMC kext to the efi kext folder.
Yes, yes and yes :)
If you set your MacOS X drive as master drive to boot from, you can select your Windows drive in the bootloader. If you want to get rid of MacOS X, just change the boot drive to the Windows drive.
I recall having issues with that card as well. Check out this link: http://www.tonymacx86.com/mountain-lion-desktop-support/93022-560ti-fermi-freeze-back-latest-drivers-10-8-3-a.html
And install the freezefix app, solved all my 560TI issues :)
My setup runs the same scores on the luxmark tooling. However, gaming wise I don't have any issues. All games run on max settings at around 60FPS (think of WoW, Starcraft, Diablo3, Metro, Bioshock3).
My guess is that those Luxmark tools are borked. What you could try as ultimate test is to...