Generally, if you are using your hotel room in an ordinary way, then you have a limited right of privacy in the room. However, if the hotel believes that you are engaging in illegal acts, then hotel management has the right to enter and search your room without your permission. Under no circumstances can the hotel authorize the police to conduct a search of your room without your consent or without a proper search warrant.
Yes there are several other legitimate reasons why the hotel may instruct employees to enter your room:
No. It is a violation of your right of privacy if the hotel discloses to another person which room you are staying in. However, a hotel may disclose whether or not you are a guest at the hotel unless you expressly instruct them not to do so.
If you feel that the hotel management has authorized an illegal search of your hotel room in violation of your right of privacy, speak to an attorney. If police were involved, a qualified attorney will be able to determine whether the police followed the proper procedure in conducting a search, even if they had a search warrant.