It is one thing to warn someone of a pending action that you -do not- support. It is quite another thing to warn someone of a pending action that you -do- support. When you support the threat contained in the message, the listener naturally feels threatened. If "threat" is not exactly the correct word for the second type of warning because the messenger isn't the one who will execute the action, do you have a better word that conveys the distinction?
I have not given any thought to what word, other than "warning", that would be appropriate under scenario #2 in your example. It seems to me that the word "warning" suffices perfectly.
If I pull out the state's law books and turn to the statute that details the definition of murder and the punishment of such action, and then I read it to you, am I threatening you or am I informing you of what the law says may happen to you if you engage in the aforementioned crime? It cannot be a threat as I am not a police officer and I have no power nor authority to force the court to give you any sentence that is not handed down by a judge who is completely separate from me.
We can make analogies back and forth until the cows come home, but in the end I have zero power over anyone, and zero influence with those who do have power, so I cannot issue threats toward any person, nor do I wish to. I have enough to worry about keeping my own self in order without being concerned about leveling threats against someone else's behavior.
God will never ask my advice on what should be permitted, and if He ever were to do so He would undoubtedly disagree with me on my judgments. But Jesus says He requires mercy, not sacrafice, and I take Him at His word that He will be understanding toward my frailty.