What cultural faux pas should I try to avoid making in Guilin?

"In Guilin, it is important to be respectful of local customs and culture. It is considered impolite to refuse food or drink that is offered to you. Public displays of affection such as kissing or hugging are considered inappropriate. When entering certain religious or sacred sites, be sure to dress modestly and refrain from speaking loudly. It is also important to refrain from giving someone the "thumbs up" gesture, as it is considered to be rude. Finally, avoid talking about sensitive topics such as politics, religion, or wealth," said another expat in Guilin, China, China.