The Church never remains a prisoner within political, racial and cultural confines; she cannot be confused with states not with federations of states, because her unity is of a different type and aspires to transcend every human frontier.
That isn't about separation of Church and state. He's just saying the Church is a spiritual entity that is above whatever associations it has with temporal states. This is true.
To look for heresies in his speeches is fun but rather pointless, because they've already set up their false Magisterium. That is why they're anti-Popes. If he had only advocated separation of Church and state in a speech, that would be his misguided personal opinion. But in reality, they have tried to make religious liberty a new doctrine through their dummy Magisterium.
It may avoid heresy, but it doesn't avoid error, and Councils of the true Church cannot even err. Therefore we know this isn't the true Church and he is not the true Pope.
The path of Christians and of the particular Churches must always confront itself with the path of the one and catholic Church, and harmonize with it.
That's a Rohrschach blot. If by "Christians" he means heretics and schismatics like the Orthodox and Protestants, the only way to "harmonize" with the Church is to join it. But that is probably not what most of his hearers will take from this speech, if they are listening to him at all. I personally think that no one cares about what he has to say, even the Vatican II Catholics. I'm sure they think his convoluted speech is weird, and they are right. The only ones who bother to read his swill are probably sedevacantists who are on the lookout for missteps.
Note to the one who calls himself Benedict: For all your talk of "love," I doubt there are many Catholics who truly love you or even like you. Does that tell you anything?