I think we can tell the difference between engineered and evolved (but note that simulated evolution is still evolution) — oddities like the path of the recurrent laryngeal nerve are cited as evidence against an intelligent designer, and I expect it isn't the only such oddity: https://en.wikipedia.org/wiki/Recurrent_laryngeal_nerve

> But I really like that the answer to a most ancient question such as "what is life" is building up to something like "it's all nanobots controlled by molecular computers"...

If you've not already watched it, I recommend this video by A Capella Science: https://www.youtube.com/watch?v=ObvxPSQNMGc&t=198s

Besides, it would be a very naïve stance to think the universe as it is today was drawn complete and definitively. There are a lot more nuanced and intricate creationist worldviews and they have been espoused in a clear headed way by some of the most fundamental characters in the history of science.

On the other topic, although the mere existence of errors would count against a supposedly all knowing and all powerful designer, that combination is not found in most religions, and not even all versions of Christianity.