> 6. North American outlets are rated for ~15A * 120V. So roughly 1800W. I can just use one outlet per psu whenever it's under 1800W, right? For simplicity let's also ignore whatever load is on that particular electrical circuit.
You're going to have a bad time with this assumption; typical non-kitchen household circuits in the U.S. are 15A for the circuit. Each outlet is usually limited to 15A, but the circuit breaker serving the entire circuit is almost certainly 15A as well; one outlet at maximum load will not leave capacity for another outlet on the same circuit to be simultaneously drawing maximum amperage.
Typical residential construction would have a 15A circuit for 1-2 rooms, often with a separate circuit for lighting. Some rooms, e.g. kitchens will have 20A circuits, and some houses may have been built with 20A circuits serving more outlets / rooms.
You're going to have a bad time with this assumption; typical non-kitchen household circuits in the U.S. are 15A for the circuit. Each outlet is usually limited to 15A, but the circuit breaker serving the entire circuit is almost certainly 15A as well; one outlet at maximum load will not leave capacity for another outlet on the same circuit to be simultaneously drawing maximum amperage.
Typical residential construction would have a 15A circuit for 1-2 rooms, often with a separate circuit for lighting. Some rooms, e.g. kitchens will have 20A circuits, and some houses may have been built with 20A circuits serving more outlets / rooms.