Nuclear Weapons and Genocides

[Bulbosław 2]

Hi, how is the idea to add a genocidal mechanic so that a foreign province that you previously conquered, which has become national for your country, ceases to be national for the previous owner and so that the entire foreign population is destroyed or completely assimilated? 

And is it possible to add the mechanics of nuclear weapons? At the same time, if more than 1 civilization has a nuclear weapon, they will try not to use a nuclear weapon if there is no significant threat to the country

And so that nuclear weapons can be disabled when starting a new game