For either sense of the word "blind", if there's a pedestrian and it's a crosswalk, the law says you're supposed to stop for them. They are not supposed to stop for you; they have right of way. If visibility is not so good, that is presumably because the highway department assumed that you, an allegedly safe driver, would reduce your speed correspondingly so that you could always see the pedestrian that you are legally required to stop for. If you are ever honking at a pedestrian in a crosswalk, or a blind pedestrian crossing a street anywhere, either your brakes have failed and you are warning them of this unusual hazard, or else you are doing it wrong.
If someone's approaching a stop sign at a high rate and it doesn't look like they are going to stop, the safe thing to do is brake ahead of time. For honking at them to work properly, many things have to happen in a timely fashion -- they have to hear you (dead people can be licensed), they have to figure out you are honking at them, they have to figure out *why* you are honking at them (presumably, if they saw the stop sign, they would stop for it, right?), and they have to react. Ideally, if the reason they were not stopping was that their brakes had failed, they would already be honking their horn.
The overwhelming use I observe for horn use is "the light is green and you're not moving". That is not a safety issue -- cars not moving is in fact quite safe, albeit frustrating.