What is the difference among these compounds?

As you point out, these are all quaternary ammonium compounds that are likely to work in a similar way (membrane disruption) and are very broad spectrum. Any differences in efficacy against a given pathogen would need to be established by empirical testing on that particular organism, as these kind of things are highly idiosyncratic--it's not like an enzyme inhibitor where you can ask whether the organism has the relevant enzyme or not. The first two are even not pure compounds, they're mixtures whose precise composition is not known a priori.

As for hazards, these kind of quaternary ammonium compounds are frequently used in topical disinfectants for use on human skin, and even in low concentration in things like eye drops that go in the eye. Obviously as with anything, the dose makes the poison, and a concentration you would use to scrub your bathroom sink is not safe to put on a mucous membrane on your body.