OK, I feel stupid. Why did I think that I needed Outlook for Shared Calendar?!?!? (because IT told me so) Apple Calendar does it just fine, even better in fact. DOH! Never doubt Apple Pinch, never! (smack on the head)
So now I have my shared exchange calendars and no Microsoft crap getting in my way, all is right with the world again. Whew!
In reply to Duke:
I know that accepting all changes is part of the process, but to be clear, I'm not the one doing that part of our process, it's various editors and copyeditors. So I can't really account for how they handle stuff, and I have a feeling each one does something slightly different. I started out doing that job, but that was so long ago that we didn't have email or the internet when I was hired. Now I just deal with the aftermath.
We do use styles a ton. They cut down on the formatting we have to do in InDesign quite a bit.
Just a bump because Apple have released the OS X 10.11.1 update today that includes in the changelog: "Improves compatibility with Microsoft Office 2016."