First things first, the flashing black screen... In some games, Guild Wars 2, for example, my screen just flashes between black, the game, and my desktop in ~0.25s intervals - This does not happen with previous drivers and when I switched I did a complete safemode uninstall with DDU beforehand... so don't go suggesting a clean install, I've tried several times, it does nothing.
And there is the crossfire issue.... If you open up crimson and go to "Preferences>Radeon Additional Settings" it opens up the old CCC style interface - if I then go to "Gaming" and try to tick "Enable AMD Crossfire for DirectX 9/10/11 and OpenGL applications that have no associated application profile" it will not apply. I push the button, it doesn't grey out like it should, Crimson restarts itself, and the next time I open the "additional options" it is again unchecked. There is not an option for this that I can find in Crimson's interface, there really needs to be... What's the point in having the new interface if it has to go back to the old one for half the options?