Coordinated turns and the little ball

Recently, Mxsmanic posted:

How much of a movement in the little ball in the turn indicator
corresponds to something you can feel in a real aircraft? And how
much of a movement represents an error large enough to affect flight
safety or proper maneuvering?

All of this depends on what you're doing at the time. One can slip fairly
drastically -- with the ball pretty far off center -- without much of a
physical sensation. OTOH, one can pin the passenger against the wall with
the same amount of slip. How dangerous any of this is also depends on what
you're doing at the time. If you're careless and go into a stall, then
it's possible that you'll wind up in a spin, which if you're close to the
ground can kill you. The bottom line is that if the pilot is in control of
the aircraft, all of this can be quite safe and routine.

Neil