Are my headers cooking my PS box?

Yep, as a kid I was trained in the art of "Armstrong Power Steering". When in tight quarters and jockeying back and forth - keep it rolling while you crank the wheel full lock the other direction so you're not fighting the friction of the tire footprint sitting still on the pavement. This being my 110lb honey's cruiser (and my tinker toy) I'd be inclined to keep her pampered with the PS. This will be just another maintenance project that happens behind the curtain.

Keep 'em coming Rusty! :poke:
Then to answer your question, I don't see the heat from the exhaust causing any problem with the power steering.