Who/what you destroy in a game is part of what I’ll call the “content”. Whether content is legal is separate from whether it is offensive to people. The law in the USA is clear that all of the game content you mentioned is allowed. (Your game’s content is considered your “speech”, and the government is not allowed to censor your speech). So you can make a game that offends or upsets people, and it will still be legal and allowed.
In Germany it is a bit different. For example there are some laws restricting a game from depicting certain Nazi things. I don’t know much about the details, but game-makers who intend to sell in Germany either avoid including that kind of imagery, or they make their German version of the game slightly different from the other versions, where the restricted imagery has been replaced with something that is similar but not Nazi.
I don’t know about the laws in the other countries you asked about.
Whether something offends people depends greatly on how it is presented. For example, plenty of Americans like games where you kill zombies regardless of whether the zombies are Americans, because becoming a zombie can happen to anyone. But if it was a game where your reason for killing the zombies was because they were Americans, not because they were zombies, then many Americans would think that was hateful. It would still be legal, but a lot of people wouldn’t like it. Blowing up American landmarks is very popular in American movies, but it is normally used to show that the bad people/monsters/disasters are very powerful, so it would work ok if it was a multiplayer war game and you got to choose which country you were playing, but it wouldn’t work as well for many Americans if they were given no choice except to be the force attacking America. To clarify, many Americans would be ok choosing to play as a foreign country and attacking America and blowing up American landmarks if they had a choice of country to play as, but many of the same people would be less comfortable with a game that gave them no option but to be a foreign country attacking America. Unless it was presented in a thoughtful way, or if you played as alien invaders from space rather than a real-world “enemy”, or any of a number of other factors…
Those are simple generalizations but it can get fairly complex which things offend people and why. Knowing whether something will offend (or more importantly - knowing whether people will really like something) often requires a lot of cultural understanding. Because you are a Chinese developer, you presumably have this cultural understanding for a lot of China, which is a very big game market. Many American game developers would like to target the Chinese market but do not have as much cultural understanding of China as you do. So I think that rather than competing with foreign games on their home ground where they are strongest, you might have better chances of success by designing a game for China, taking advantage of you having knowledge that other developers don’t have.