Amy infection: I tought we settled that: during the autopsy
Tanya notes the little one has self-inflicted wounds. They "poison" their own nails with their blood and infect with the scratches. I agree that until now, with the one exception of the slow turner who bit Tanya, we had only fast turning. Which is what made the fall of Boulder so unconvincing to me, people turning after more than 24h in a car (plus other convenient accidents). Funny enough, Amy's own slow turning makes sense now in light of the fact that slow turners were in the convoy.
I think we should discuss the absence of the "this is now" line from
Michael's initial speech (plus he seem to stammer on "didn't"). It is a significant difference that sets this season apart, KC does not do things like these randomly, he usually is very deliberate and takes great care to chisel even the smallest details.