I will add that I just received my 970 today, with similar settings to the OP's latest settings, except shadows on medium, cockpit displays at 512, and MSAA at 4, I'm averaging 55FPS in the MiG-21bis during takeoff.....with 3 monitors.
Keep dropping that MSAA, it will help a lot, but that AMD along with it's relatively low clock speed will hold you back some.
Also drop the pre-load radius as low as it goes, you're just increasing your load time.