This is something I’ve never heard of happening,. ..
The “Sky light” setting, is in a different section. (Global illumination)
Anti-alias settings for Pixel accuracy, and Shadow accuracy are in the main rendering settings,.
I’ve never seen those two anti-alias options “ghosted” or unavailable as options. any screen shot’s ?
The Lighting Quality, and accuracy settings are part of the Global illumination options, and those would normally be ghosted, until you activate the Sky light, or Indirect lighting.
In Carrara, you can save a “Preset” of your (Good scene) renderer settings, as a file which you can then load back into the renderer settings in another scene.
the save / load icon’s are at the top of the renderer settings. (see pic)
Click thumbnail to see full-size image