I want to move away from GSF, how is MicroG working nowadays? I used it some years ago but it was buggy with any app related to mapping, and some other quirks.
Works perfectly fine for me. I've also used an app that used Google Maps in it and it worked perfectly fine. Instead of Google Maps it displayed the map on OpenStreetMap.
No. Banking won't work and you can't lock bootloader. As far as I know there's no Recovery password so someone could just adb and pull data. If you want to use banking apps you could use magisk to pass safety net but that will make your phone less secure. Personally I have no banking app so I don't give a shit