These are just big fat lies that are being spread by the politicians that lost last elections. None of this is actualy happening in Poland.
Minorities are just fine, no action has been taken against any of them, citizen rights are in fact better than in most EU countries (no "political correctness") and the separation of church and state is ensured by the fact that 90% of Polish citizens don't treat their religion seriously anyway.
The one thing that makes some sense is accusation of constitution violation, but this has more to do with the fact that Polish constitution is poorly written than with any actions of PiS.
And, as a side note, PiS (ruling party in Poland) is of left-wing, socialist affiliation:)