The third option - accessing only browser sites - is under appreciated. I never needed to install Google's MDM on my mobile devices, I just used mobile web gmail and so forth. It's great, honestly, and the mobile web Calendar has the advantage that it doesn't destroy your battery life like the Calendar app will.

I even saw a guy using the code review site on his mobile, on BART. That was dumb from the standpoint of infosec, usability, and mental health, but shows how much is possible in the browser.