it gives you, without a boogle account, access to apps you can only find on 'play store'

It's "good" for what it's written for

on lineageOS, for bank apps &c, you probably need it

Yes. Not sure about its moral compass though.

I use it, albeit logged in but without MicroG, and it works as I'd expect. Dunno how anonymous browsing is going these days though.

You don't have to. There's an anomymous account option at startup. However, from time to time, there may be problems with app download on such accounts.

Yes

It seems fine. I use it with a google account.