Yes to this. Not only could we find the correct original DNA sequence by statistically looking at a large number of cells- the fact that biology can't do that

Yes to this. Not only could we find the correct original DNA sequence by statistically looking at a large number of cells- the fact that biology can't do that might explain why (almost) all living things age. If you can't error correct statistically, (and evolution can't since earth biology can't compare multiple DNA strands at once) then you have to prune the mistakes by reproduction followed by death if the new organism has defective DNA.