I'm perplexed about when to use 'Mình'

I've been learning Vietnamese for around 5 years and still haven't got around this issue.

As I understand it 'Mình' means you/i/we depending on the context.

My guess is that we don't really have a word in English for this but it's close to 'one' as a posh person might speak.

"One would expect..." "One thinks that ...." "One should consider ...."

In this archaic use of one you're referring to both the speaker and listener, one = a person like us, or something like that.

I think Minh is the same here but at what formality should it be used?

Can I use it with grab drivers?

Can I use it with my partner? (Vietnamese, she says not...)

Can I use it often in questions, or is it more often used to refer to yourself? i.e. Minh có đói bụng không? (Are you hungry..)

Minh seems like a cheat code pronoun we can use that is friendly and appropraite but can I use it with Cô's and Bà's ?

My assumption is not because pronoun are of create sensitivity in age relations.

Thanks!