I didn't know Play store signs App bundles, developers can give the key to sign it but still Play store builds the apks for installment. They have a feature that developers can inspect if their code was changed but I dont trust that every app will use that feature.
From android source: https://developer.android.com/guide/app-bundle
An Android App Bundle is a publishing format that includes all your app’s compiled code and resources.
Google Play uses your app bundle to generate and serve optimized APKs for each device configuration, so only the code and resources that are needed for a specific device are downloaded to run your app. You no longer have to build, sign, and manage multiple APKs to optimize support for different devices, and users get smaller, more-optimized downloads.
I want to switch to Aurora store since they can install app bundles. I'd rather trust them build the apks than Play store.
From graphene wiki ( https://grapheneos.org/usage#sandboxed-google-play-installation ) Play services and the Play Store depend on each other, one will not work properly without the other. Both of them depend on the Google Services Framework app.
Since I can not remove play store, does Play services and gsf work properly without sign-in. I dont need to sign-in to aurora store so I see as redundant to sign in to play services.