I tried several procedures.
The following steps were very helpful for me.
1. Lumia Recover to 8.1 and when it has installed, select New Phone (don't recover a backup)
2. When installing 8.1 - be sure to select Language and Regional settings to English ( USA ).
3. When complete, make sure to update all build-in apps via store - then install Windows Insider as last.
4. Active Fast Circle in Insider app (it will prolly reset) - then update to Windows 10 Indsider.
5. When Update to Win 10 is complete be sure Not To Hard Reset ever. It somehow screws with in-build apps.
6. You will still receive some errors when updating some apps, but try to reboot, or control what installs manually.
7. If you have the need to Hard Reset - do these steps again.
Hard Reset after updating to Win 10 build 10166 is not recommended
This made all my apps happy, and gave me more control back.
Well known bugs are still here ofcause, like Pinning.