"Can I fully control my Android phone?": No, you can't.
– in our tests, AFWall+ leaked DNS queries of all apps on the device (including blocked apps), making it easy to determine apps installed on the phone
– updating Android doesn't imply that firmware vulnerabilities get fixed
– apps from F-Droid/Play Store etc. can still leak personal data as shown in our /e/ article
– besides, your proprietary baseband processor, GPS, sensors etc. remain out of control