No.
People who aren’t usually are never 2 faced.
People who are tend to be 2 faced with almost everyone except a handful of people.
I’m not sure which % fall into each category.
Those are what I like to call the People Trying To Sell You Things (PTTSYT). While they can be extremely annoying, their two faces are occupational rather than a personality trait. I’d agree that almost all of the PTTSYT are two-faced, but that says nothing about people in general (or even how the sales people behave when they are off the job).
I think that most people have generally good intentions; however I would never want to have the power to read minds.
I would say yes, but maybe that is projection of myself onto others. I’m sure everyone has lied, though not sure if that is synonymous with being two-faced, I also think there are certain situations where lying is not immoral.
I know this guy Janus who is very two faced.