The fourth rule just broke physics harder than a dropped beaker in a silent lab! In reality, neutrons are actually heavier than protons by about 0.2% (1.675×10-27 kg vs 1.673×10-27 kg). This is like asking someone to make water flow uphill or electrons to suddenly have positive charge.
The joke plays on the format of supernatural wish-granting beings with arbitrary rules, but instead of the usual "no wishing for more wishes" trope, it throws in a completely impossible physics demand. It's basically saying "I'll grant your wishes, except you have to rewrite the fundamental laws of the universe first."
Next request: make entropy decrease in a closed system while you're at it!