I use Windows, Mac OS X and linux on a daily basis. I use git in all these environments, pulling from repos that are used by folks with different choices for line endings.
Are there definitive recommendation for setting core.autocrlf in my situation?
I would recommend, as I did in this SO question, to set it to false.
If you can avoid modifying any eol (with your editor), then it would be best to push back your work with those eol unchanged (i.e. "as you found them").