I’m not fully up to date when it comes to e/os as I haven’t used it before. I believe it would be more private than the default os on fairphone considering google has been stripped out. I’d recommend doing research on the security updates of e/os, as if I’m not mistaken, these can often be significantly behind leaving you vulnerable.

If security updates aren’t quickly implemented, as I think they’re not - I wouldn’t recommended using it.

If you’re using a VPN try connecting to a server in Albania, I’ve never had issues when connected from there for yt

Since you’re on grapheneos you could always set up the 2 factor unlock when using biometrics. You would then unlock your phone using fingerprint and a pin. This way even if you’re forced to unlock the device they’d still need your secondary pin to unlock. The pin can be much shorter than your main password so its still fast to unlock.

Privacy policy says they keep logs of browsing data for 6 months.

I’ve had no issues personally with my banking apps. Most require sandboxes gPlay to be installed but there was no need to be logged into google for them.

Not sure now up to date this list is now but check out this site: https://privsec.dev/posts/android/banking-applications-compatibility-with-grapheneos/