This is a vent pipe for a gas water heater. It is not connected allowing carbon monoxide to escape, possibly getting into the living space.
This pedestal is open to the rain. It has 110 and 220 volts open for any kid to get electrocuted .
This is an A/C unit without a secondary condensation drain or safety switch . If the primary gets clogged up it will allow condensation (water) to leak into your house.