Here is a decent enough summary of GATTTOTP:
In State v Huntley, it was determined that a gun does satisfy the requirements of being an unusual weapon in that case, but since OC is not determined to be illegal in NC (although it's practice can be restricted in certain situations), simply openly carrying a gun is not enough to be subject to being charged with GATTTOTP. A few conditions must exist before the charge is valid, such as intentionally causing terror in public with a gun, etc. Openly carrying a gun is not a crime, but using that gun as part of a crime is, and therein is "supposed" to be the difference.
Even the circumstances which you introduce, being a black man with a gun, is not enough for a crime to be charged. Carrying a gun is openly where not restricted is not a crime. Being black is not a crime. Being black and openly carrying a gun where not restricted is not a crime. However, carrying a gun and threatening others with it on a public way *is* a crime, whether or not you are black and could you with being charged with GATTTOTP, along with other possible charges.
Much of it comes down to the *intent* of the action where a gun is involved. But, the vagueness of the law sometimes comes into question.
Please take all of this as my opinion as I am not a lawyer. Others will have opinions as well, which will be just as valid.
All in all, it's not a very commonly used charge, especially when used as a stand alone charge. It's normally tacked on with other charges, but it's not limited to that condition.
You can never know when your rights will be violated and that's not limited to back men when it comes to the entirety of law enforcement. None of us can be sure that our rights won't be violated in some way, especially while we openly carry a gun. My only suggestion would be to become thoroughly familiar with state, local, and Federal gun laws, carry some kind of recording device when carrying, and to never argue or threaten LEOs if you come in contact with them as a result of simply carrying a gun openly.
Know your rights and don't consent to illegal searches, but don't physically resist, either. Again, just my opinion