May I ask how you installed microG?
Install microG GmsCore, GsfProxy, FakeStore (or Play Store if you want so) and MapsV1 to /system/ - nift4/microg_installer_revived
github.com
You can also use the real play store, but you must configure that yourself, its very easy. You can still use in app purchases and paid apps. I don't use android auto or have a watch, so I'm not missing that functionality, but microG has been mostly transparent to my experience, it doesn't really seem as if I am using something different, everything for the most part just works, not to mention the increase in battery life. AGPS works just fine, but make sure to install your location modules from fdroid. The Dev of microG seems to be picking up development here and there, its nice to have an alternative to Google, but not lose too much functionality.
Sig spoofing for the microG app is built in to the ROM so nothing needed on your part, just flash it and it works.