>>>We are just concerned. And I do not warship Google. The opposite. :)
>
>Right. I've moved my email on Android to K-9 with email servers reasonably private at gandi.net. Messenger now is largely disused. One thing I did learn is that if you dissociate your gmail account, it kills all your contacts whether sourced via gmail or not and denies access to Play Store. Easy enough to set up a dummy gmail for the store and to keep all your email elsewhere IME.

I run my (e mail) server under my desk.It's a high powered NAS.
For the contacts. You can store them to the phones inventory (there is a number of possibilities where to bound the contacts) This is not synched with google, at least it will survive a change of accounts. It is possible to set up an own server for the calendar and contacts on a linux machine. (google mostly uses open software, ;) )

Also note, if you run more then one Android. You can have multiple accounts on a phone and the same account on multiple phones. The store and contacts etc will distinct them. Why not put all apps to one account? It will be available on all phones (up to 3 or so are allowed, says my daughter. School yard knowledge). And for some stuff a synch is not that bad. Or at least more easy.
Also it is possible to remove the google plus stuff from a google account, it's a bit hidden, but there is a known search engine in the web.

The only thing that I dislike on K9 is that I can not read plain text only. HTML does not belong to an e mail.