I've always been sort of comforted by the notion that whether or not we destroy the Earth for most life, the planet itself goes on. It's wiped clean of life, but life probably rises again and so things go on as they should, maybe with some sentient lifeforms wiser than us.

I'm not so sure I like #2 or #7, they seem a bit more nerve-wracking.

So the poles reverse...I don't see how that, alone, wipes life off the planet. It's happened regularly in the (distant) past.