69c is fine and no MSI Afterburner does not interfere with Catalyst.
1.Open Afterburner, click on "settings".
2.Open fan profile, choose your curve, press ok :
3. Use the bars to slide the clocks.
4. Press "Apply" and you are done.
In games your card should not go over 60, when stressed with kombuster/furmark it should be in the 70's at most