> If the police stands in front of my house with a warrant to search my belongings, can I refuse that? Does it make sense if I have nothing to hide?

Why don't you take the advice from someone who knows what he is talking about. If you're in on a hurry make sure you see part two:

Part one: https://www.youtube.com/watch?v= interrogation (Mr. James Duane, a professor at Regent Law School and a former defence attorney)

Part two: https://www.youtube.com/watch?v=08fZQWjDVKE (Mr. George Bruch police officer, years of experienced in suspect interviews for the police and US navy.)