Do you always apply a limiter to the Stereo Out of the Mixer for a project? If so, at what settings?

No. And if yes, then at the settings that are necessary to get the wanted results with a given mix

The only thing I apply in the final mix is compression. With that I can also adjust it’s level if I want to keep the stereo fader at unity. If I’m going to cd or mp3, I also use dithering.