For the calendar: I need to access a google calendar from work and it kinda worked by adding a google account in system settings. Kinda. Every 2-5 weeks I noticed that the calendar was not syncing correctly anymore. I had to remove the google account from system settings, add it again, uncheck all items I did not want syncing (mail, contacts, etc.) and everything worked fine again for a while. But the conitnuuos uncertainity if syncing was working was unnerving. I suspect the problem has to do with the inbuilt “stealth” function of micro-g, which prohibits google to continuuosly identify my device, so at some point google servers refuse to sync.
I then tried to access the google calendar via webdav/caldav, that never worked for me.
Now I installed an app called “ICSx5” which allows to add accounts for the iCalendar standard format. Google-Calendars provide a private ical-address for each calendar. I just noticed, that this is only working for viewing though, I don’t seem to have write-access from my phone 
