Travel Vaccinations for China?

You seem overly worried. There are no unusual health concerns in China, except for the risk of tropical disease on Hainan Island. Note that British NHS is meaningless in China. You need to carry sufficient cash with you at all times to cover possible medical treatment. You need to pay first, then you get treatment. That's how most of the world works, so don't be afraid. You would face the same issue in the United States because without a USA health insurance card or cash payment, there is no treatment.