Okay, seems how there's nobody out there that can help me is there ANYBODY out there that has crossfire working, if so what drivers are you on?
In my case, RF2 doesn't work in crossfire with new 14.4 and 14.6 drivers. The 14.1 and lower generation works fine, but with those newer ones I got a lot of flickering, missing textures etc., totally unplayable. And all other games I have works fine, so I guess that can't be a driver problem.
I have 14.7 RC running in Crossfire. I use RadeOnPro for some detail tweaks. Crossfire work in AFR and default mode. I noticed with AFR crossfire rendering some flickering but much higher fps output then with default crossfire rendering. When disabling the enviroment reflection in rF2 the default crossfire rendering is the best choice in terms of fps and image quality. I will try the 14.1 today or im the next days to compare crossfire's performance with 14.7 RC.