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

"1. Respect religious and cultural differences, be mindful of personal space, and be aware that American English has some nuances which could be easily misunderstood. 2. Don't make assumptions about people's political views or beliefs. 3. Avoid offensive comments about politics, gender, race, ethnicity, nationality, age, or sexual orientation. 4. Don't stare or point, and maintain a respectful distance from individuals you are unfamiliar with. 5. Respect the importance of privacy, and don’t make assumptions about relationships or personal histories. 6. Always ask permission before touching someone or making public displays of affection. 7. Dress appropriately when in a professional or public setting, and avoid discussing contentious topics such as religion or politics. 8. Show gratitude, and remember to wait your turn when speaking in a group," remarked another expat in United States.