Response to point 1: I know this.
Points 2, 3, and 4: The intent of any words can be indicated by the speaker's non-verbal communication. I have said every one of these with such things as a smile and
a conspiratorial twinkle in my eye, and have yet to be
rebuffed or misunderstood.
I agree that if any speaker is not comfortable with the language he or she is using, it is quite likely to
sound stiff and forced.
FYI--I am not about the fact that your office staff,
or anyone, uses the term guys when talking to females. I
am angry because you are amused at the situation. I can
even, in a way, see why you are amused, but I don't have to
like it! No hard feelings here. I still love (usually!)
reading your posts.