Listen, it's VERY simple:

Classify the weapon (pistol vs rifle). Then, observe the laws that are used for said type of weapon. If it is classified as a pistol, then you need to observe pistol carry rules. If it is a rifle, then you observe rifle carry rules.

If you want my opinion, that is a rifle. It is a "shorty" version of a rifle, but a rifle none the less. They try to call it a pistol to avoid having a stock, folding or not, and a 16" barrel, but you get the idea. You might want to check on the legality of that weapon in terms of its classification. If they will classify it as a pistol, then that answers your questions.