If you can only jump off a 4-foot cliff on Earth without getting hurt. 
I think I’ve jumped further than that without injury.
Also, FoamFighter, your location is confusing. Shouldn’t it be 39º 37’N, instead of 38º 97’N? On my map that puts you about 10 miles west of Prettyboy Reservoir.
Yes, also assuming that the lowered gravity didn’t cause you to misjudge your leap and land head-first or something.
Actually, I live in Catonsville. 
You also need to keep in mind the mass of the space suit. That could easily double the energy of impact. Of course the suit could potentially give some “crush space” to decrease the de-accelleration (I know there is no such thing).
No, not if the Moon is properly hollow, i.e. a relatively thin shell with relatively small openings at the poles. There’s no gravitational acceleration inside a spherical shell. If you’re off-centre, the attraction of the near side is balanced by the attraction of the greater mass (more area in your field of view!) on the far side.
Unless you’re in Pellucidar.
Once I fell 5 feet on to my back (in Earth gravity) and walked away; guess that means 30 feet on the Moon wouldn’t kill me. 
Is that because they both obey the inverse square rule?
Yes.
Actually, that’s probably not the best way to say it, though I think you have the right idea. The amount of mass per solid angle goes as the square of the distance, and the amount of gravity force per mass goes as the inverse-square of the distance. So they cancel, and the gravity force per solid angle is constant with distance. (Solid angle is the measure of “field of view”.)
You don’t fall on the moon; you and the moon fall toward your shared centre of mass.
Well that’s also true of Earth but in both cases the center of mass is so close to the center of the celestial body that for all practical purposes it makes no difference. For that matter, the Earth and Moon revolve around a common center of mass but that center stays a few thousand miles below the Earth’s surface at all times.
i think, technically the original question is somewhat flawed, as the moon holds no water, therefore there are no coastal erosive processes taking place and therefore, strictly, no CLIFFS. but we all know what you mean.
Well, according to this site, the Moon has at least one cliff:
That would be quite a fall though, and it’s doubtful anybody would survive it even in the Moon’s gravity. :eek:
Even if there are no erosive processes on the moon, a sizable asteroid could create a nice gash in the surface.