It's beautifully written, and I love the idea that our biology is alien and terrifying to the Thing. But I dislike how it rewrites the idea that the Thing is not some wholly communal organism, each part unaware of the others.
Each part contains multitudes, but is in itself distinct, alone, trying to survive. That's why the blood test works, why Norris falls apart and turns into multiple organisms all trying to cut loose:
The Thing wants to survive -- but the Thing knows it only needs a single cell. You can cut and burn and obliterate countless pieces of it, but so long as one cell lives, everything it ever knew, ever was, survives. So the blood can try to run off, knowing that it makes no difference if you torch the rest of Palmer. So long as IT escapes, the Thing survives.
The idea that Childs and basically everyone else was the Thing for a long time really undermines the entire, terrifying point; that the Thing knows it only needs the smallest part of itself, and that it will do anything to ensure that small part survives.
Even if Childs and MacReady aren't the Thing, there are cells -- fragments of flesh, blood, tissue -- frozen all over the place. Any one of them could thaw, awake, and begin again.
