re: It's going to be tricky for JPL engineers to keep Opportunity out of the crater's shadows inside.
Yes, but being in the crater also gives them the "opportunity" to park on the back slope with the solar panels facing more directly at the sun, and to move around the crater from morning to evening, following the sun, like a basking lizard.
I suspect it'll go wrong, though, and one morning it won't waker up after a bad day with too much shadow, but that's life and death on Mars for you, if you're a machine.