No, the police can not legally "kick the shit out of you", they can use reasonable force if you decide to ignore or refuse instructions when they have a warrant which has been obtained via the courts. The warrant will only be granted after presenting substantive evidence that the person they are wishing to arrest has committed serious crime i.e. possession / distribution of indecent images of children, drugs, money laundering etc which required rapid entry to secure evidence. They don't get to enter your property for minor offences or on a whim.