Since this IS business a smile wouldn't hurt, but THAT would be about the only carrot I'd extend.
Basically you are treating him like a co-woker now, NOT a husband. So there a small ammount of if not pleasantness...at least not hostility coming from you. You both work together still.
As for letting your almost adult daughter form her own realtionship with her dad.
I think the key words here are :
almost adult
You're the mom, since dad is currently a fcktard, and the one she is currently having issues with, it is your job to protect her, pysically and mentally.
You leave this up to her all by herself and she is likely going to be one of the countless women out there who have daddy issues later in life.
Guide her and help her with those isssues NOW.
Experience is a brutal teacher, but you learn. My God, do you learn. - C.S. Lewis
Life is usually all about how you handle Plan B. - Jack3Beans
Listen without defending; Speak without offending - FaithinAK