NASA claims that the space suits worn by the astronauts were pressurized at 5 psi over the ambient pressure (0 psi vacuum)

Well, 3.5 to 5 pounds.

We have examined the gloves NASA claims the astronauts wore and find they are made of pliable material containing no mechanical, hydraulic, or electrical devices which would aid the astronauts in the dexterous use of their fingers and hands while wearing the gloves.

One wonders if they were looking at the gloves or at the glove protectors.

Experiments prove absolutely that such gloves are impossible to use.

What experiments? We are baffled at how the experimenters were able to pressurize the glove, with a hand in it, without the rest of the suit. As an engineering student at Kansas State University I was on a team which designed the glove protectors for the shuttle EMU specifically tailored to facilitate operating the MMU. It's really quite a trick to pressurize the glove for testing.

NASA actually showed film and television footage of astronauts using their hands and fingers normally during their EVAs on the so-called lunar surface.

The astronauts sure complained about how hard it was to use their hands in the gloves. "Normally" is an unwarranted.

The films show clearly that there is no pressure whatsoever within the gloves

What you see on the EVA video are the glove protectors. The pressure gloves themselves are black and attach to the wrist by a ring lock which is pressure tight. Then over the top of those you put the glove protector, which is not pressurized, but which has the thermal insulation and the silicone rubber fingertips (same material as the boot protectors) to keep from puncturing the glove itself.

Clearly these "researchers" have no idea how the Apollo EMU was constructed or used.