McDuck for banking apps are you sure you need play store ? My banking all has a notice when I open that it requires play store but works fine without it.
Google camera doesn't need play store , it won't let you view gallery from the camera app but other wise works fine . this may not be acceptable to you .
You must sign in to owner profile before signing into any other profile .
For me any app I considered spooky I make sure to put it in a profile I can turn off .
Just another suggestion , if you have experienced any lock screen issues ( finger print ) I'd suggest reinstalling grapheneos from scratch . I had them and just doing a factory reset didn't fix it . (/before you set everything up )