Unfortunately, Gamma Correction is a feature exclusively found in the Pro series.  For any other version, this will need to be introduced into your materials, a long and drawn out process which I wouldn't recommend unless you are willing to convert many items to new shaders.  Bantha did create a script for the Wacro to automate this process.  Light based AO is inactivated by IDL, however I do know that material based AO, present in PP2010, can be considered under IDL rendering.  I don't know if the same feature exists under installation of SR3 for P8. 

Definitely, install all the service packs available; there have been some major fixes which will make the workflow easier.