It looks like you already know this, but you CAN'T try to "figure out" waywards. They're simply all over the map, and projecting so much that is out of their true character, that it's a fruitless (and sometimes, even counter-productive) exercise.
Focus on YOU, DETACH, and DON'T ENGAGE her in R talks other than to see if she's ready to leave OM and agree to your terms to work on the marriage. Until she is, "separation" is a legal issue best left for the attorneys, and you should say precisely those words.
