I suspect that the "don't eat toothpaste" stuff is mostly overblown and primarily just to ensure kids don't eat toothpaste like candy (which kids will do). In large quantities (say, a whole tube) it will make you throw up, and maybe you could accumulate too much flouride.

Is a pea-sized drop on your toothbrush going to hurt you if you swallow it, no, but there's no reason to swallow toothpaste and a number of mild reasons why you probably shouldn't.