As you outline, only a partial blocking is possible when google services and applications are on the phone (today this includes most apps from the g-store). A

As you outline, only a partial blocking is possible when google services and applications are on the phone (today this includes most apps from the g-store). A "pure" analytics service may be blocked when reaching to a known spyware server. Bundled spyware and telemetry (is that "google core") are unfortunately not blocked.