Animals are absolutely a primary vector for infectious disease. No, there's no definitive evidence as of yet of patient 0, though the cluster of early cases in China had strong connections to the wet market in Wuhan. It's not necessarily the eating of the animals directly, but indirectly – because wild animals are kept stressed, in cages, next to other domesticated animals and people.

Even with conventional animal agriculture, things like bird flu and swine flu are a serious threat.

Well, it's linked to bats (like many such illnesses). One of the biggest exposures to these animals is at such markets, so whether or not this particular outbreak is traced to a particular market is less important than generally lowering exposure.

> Yes, the press has reported that a market in Wuhan sold exotic animals, but it seems this is uncorroborated, and after asking an acquaintance in Wuhan about it, I was told it's fake news, and that said market sells farmed animals as far as she's ever seen.

Fake news, seriously? There's an entire wikipedia article about it: https://en.wikipedia.org/wiki/Huanan_Seafood_Wholesale_Marke.... Please verify your own news source before spreading more fake news/

The Chinese government appears to be trying very hard to not be blamed for it and is spreading fake news of their own, which is what your acquaintance may be telling you.