Suppose I'm in Russia, as a foreigner with little knowledge of local culture. What things should I do as to not irritate/get on nerves on others? Like not to come off as rude or unpolite or showing disrespect to people/culture

TLDR - What things I should avoid doing in Russia because it is rude and uncool?

I learned these things so far -

1. Do not smile under any circumstances, always keep a straight face
2. Do not ask anyone about the war (Great Patriotic war ofc) unless they talk to you about it first.
3. Stay away from shady places and trust gut feelings.
4. Do not underestimate the winter temperature
5. Always keep sandals outside when entering house/apartment
6. Do not refuse anything that is offered to you in a public function (like if you are invited to dine with your friends family)
7. Do not get into arguments with anyone, especially while driving. Always make sure you cam is working.

What else should I watch out to survive?