You are allowed to use any preset, as long as the only change made to it is setting the number of evidence to 0.
Technically yes, but we don't require players to rule out mimics when going off of ghost behavior for any% and trueany%, because basically any ghost behavior that isn't directly tied to an evidence type could be a mimic so it would slow down the category significantly.
I know this is a 5 month old comment, but there's a setting you can choose to use text selection for spirit box, Ouija board, and monkey's paw
If you are running any% then yes you are allowed to rule out ghosts if a behavior is performed that absolutely cannot be that ghost. Just like in your examples with stepping in salt, seeing dots in person, or another example being the breaker getting turned off.
So that noise you heard which sounded like a ghost event was one of the Deogen's special behaviors, where it breathes heavily through the spirit box.