It's easy to tell wild from feral. Offspring reared in the wild from feral hogs are wild by anyone's definition. "Wild Boar" is a very vague term for any wild hog. As we all know, a boar is male.
Most feral hogs will have tell tale signs like ear tags, clipped tails, ears and teeth. And if you shoot one in Missouri, the legal owner can still claim it and prosecute for killing it. Seen it done down here a few times. And they all can carry disease, wild or not.
As a farm raised kid from a huge hog production in Iowa, trust me when I say this; just because they are fenced and raised on silage, don't mean they're tame by any stretch of the imagination. Piss off a sow with piglets and find out. Same holds true in the wild. Sows are much more intimidating to me than boars. We hunt them here and in the Ozark National Forrest near Fallsville AR. And you are right about the shore. They are very common on the Northern shore of Tablerock Lake. We also take a rifle when we fish down there.