When you said "I'm getting continuous power to the green wire" , did that mean the hot lead comin out of the car to the wiper motor? I'm pretty sure you covered all your bases on this one though. My wiper relay and combi switch both went bad and the symptoms were nothing like you're describing.
When the relay went bad, the wipers still worked in intermittent, low, and high, they just didn't park. By that i mean they didn't return to the bottom of the windshield after i turned off the wipers.
When the combi switch in the steering column went bad, the wipers would turn on and off on their own, stay on after i turned them off, turn off when i had them on, etc.
I'd say you did a damn good job figurin this one out!