First two are weird and culty even by the standards of religions, but as long as they keep to themselves and abide by the law i guess there isn't much that you can do about them. The last one is different, it's not a religion, it's a predatory and very likely criminal organization that is about the same level of fucked up as human traffickers. They should be outlawed in all countries and its leaders arrested. They are the Western equivalent of Falun Gong.
They are cults, Mormonism is the logical conclusion of US cultural messianism and Protestantism, it is American exceptionalism in the form of religion.
Jehovah's Witness I don't have much knowledge
Scientology is an obvious scam, and a criminal organisation.
Europe does not in general have a cult problem, but US based cults are slowly expanding into Europe to grow and take advantage of people's general sense of a decreasing quality of life.
Cults solve three issues for the bourgeoisie in the USA, SK, and Japan:
It perfectly internalize the revolutionary energy and/or channels it away into the cults organization.
It gives a sense of community in places that have been devastated by hyper individualistic ideologies.
It can deliver powerful anti communist propaganda and capitalist apologia disguised by the "word of god". (This is what I have seen in Latin american evangelicals that receive preachers from the USA). In other words, the "Prosperity theology"
That's why cults prey on the needy and the helpless within the working class. It is an effective way to disorganize the working class with messages such as: "pray to god so you can have prosperity" or "Poverty is a curse of god and it means that you are lacking x y or z characteristics to be a perfect follower of the cult"
Insane sect that theocratically runs a state, relatively harmless cult disconnected from the real world, crazy cult that tried to take over the US government and other stuff (I know Evans is a fed, but I think I liked the behind the bastards Scientology series).
My parents are Jehovah's Witnesses. They are 100% detached from reality and it sucked being raised into it but they are staunchly pacificist and non-political so they are at least benign in my opinion compared to something Falun Gong.