No, they don't. Many countries have the concept of "imminent danger", which allows police to skip the warrants. It's called "Gefahr im Verzug" in Germany, for instance.
Depends on where you are. In the US there's the Exigent Circumstances exception to the warrant requirement. Not sure if the same theory has been included in EU countries but I would be surprised if it hadn't, a quick search didn't turn up much english language about it.
Well, there is actually an exception to that too - the Police can break into any home, without a warrant, in the US, if they can prove they had reasonable cause to believe that there was imminent and immediate threat of bodily harm or death.
If you are a police officer and see a guy clearly pointing a gun at someone else through the window, yes, you can break in if the circumstances warrant that.
The flip side of that is that if the police enter on that basis, any evidence they come across in the course of that action is going to be tainted and potentially thrown out of court, especially if that evidence wasn't in plain sight.
That's not true at least in Spain. There's "In flagrante delicto" which means if the police suspects something going on they can kick your door down.
It was used many times during the pandemic: when they suspected you were having too many people over at home, they acted. Unconstitutionally, mind you.
The constitutional court of Spain ruled the state of alarm (a kind of state of emergency) that was used to prohibit gatherings during the pandemic was unconstitutional. But by then the damage was made of course.
The constitutional court of Spain is an ultra-rightwing joke. Imprisoning Catalan nationalist politicians for calling for independence brought that court into disrepute.
I'm not keen on written constitutions, or constitutional courts <cough US Supremes>.
Errr, that's not exactly what they did, as well as you know :-)
In any case I hope we can agree that it's good that they said that restricting our constitutional right to free movement was illegal, even if it had no consequences for those who violated our basic rights so blatantly.
If I'm wrong about the constitutional court sentencing Catalan nationalist politicians to prison, that's not something I know; feel free to correct me.
I don't know what that has to do with free movement, nor how that's related to the imprisoned politicians.
FWIW, I don't accept the notion of "human rights" - there are in reality only those privileges that are actually granted. I would like it if there were some kind of universally-accepted set of rights; but only if they are congruent with my own views about what "rights" should look like.