boss threatened me with demotion, when do you know it's a scare tactic or legit?

Question

Or is it a combinition of both?

Answer 1

The boss has no need to use scare tactics, he or she can actually demote you if you do not meet job performance requirements. You should assume that the possibility of demotion is very real, and either adapt your performance to meet requirements or start seriously looking for a new position.

Answer 2

I would assume it's real, based on everything you've already written. Generally, though, bosses don't use scare tactics, they tell you what your future is going to be unless you implement change.