Using GTA 5 mods in single player mode will not get you banned, according to an official statement on the matter from Rockstar. In the newest ‘Asked & Answered’ session, the studio has (somewhat, but not entirely) cleared up their stance on modding.
“To be clear, the modding policy in our license has not changed and is the same as for GTA IV,” the statement reads, presumably in reference to the bogus EULA story that was doing the rounds recently.
“Recent updates to GTA 5 PC had an unintended effect of making unplayable certain single player modifications. This was not intentional, no one has been banned for using single player modifications, and you should not worry about being banned or being relegated to the cheater pool just for using single player PC mods,” it continues.
That, then, is the official green light for single player GTA 5 modding. It also suggests that the studio are not actively trying to shut down single player mods with game updates.
GTA Online, however, is another matter. “Our primary focus is on protecting GTA Online against modifications that could give players an unfair advantage, disrupt gameplay, or cause griefing.”
While it isn’t made explicit, this part of the statement does, unfortunately, imply that even things like an FOV mod could land you in trouble in GTA Online. Seeing slightly more of the screen (even if it’s just to prevent you getting motion sick) could, in a very uncharitable reading, be construed as an “unfair advantage.”
That’s harsh, but it sounds as if even fairly harmless GTA Online mods are in a “use at your own risk” situation.