Can I connect the supply power for the servo to a digital out pin on the Arduino instead of the 5v out pin, and then simply drive that low instead of detach(), and drive it high inst
Some here on the forum would say yes, go ahead, you won't damage your AVR in any way, powering your servo through an I/O pin.
The sensible ones would say don't even think about it.
What happens when you simply detach?
I'm tempted just to try this, but figured I'd ask and may save myself the cost of a fried servo.
You'll be happy to know your servo would survive.
Not so your Arduino.