How much should I stay away from 0db?
I personally follow 2 lines of thought.

In my audio-digital pre-history, when I was learning Cubase, I read this advice: try to keep the levels at roughly -3db if possible, so they have the room to hit 0db.

On the other hand, someone once asked (the blind) Ray Charles in his studio: how do you record here when you don't see the meters/levels?

He replied: if it sounds good, than it's good, isn't it?

my 2p.