1. The most obvious charge just for entering is criminal trespass. However, that usually requires some type of warning or notice being given to the person telling them not to enter the premises OR that the premises be surrounded by some type of fence. However, the fact that his keys were taken from him and he is using a set that you were unaware he had should get around the warning or enclosure requirement. Entering a building, as opposed to a residence, is a class B misdemeanor
and has a potential sentence of up to 90 days in jail.
2. The "messing with people's stuff" really doesn't raise the level of the crime past that described in #1.
3. It is a felony to overhear or record, through use of an electronic or mechanical device, a wire or oral communication without the consent of at least one party to that communication. Ky. Rev. Stat. Ann. § 526.010. A person is guilty of eavesdropping when he intentionally uses any device to eavesdrop, whether or not he is present at the time. Ky. Rev. Stat. Ann. § 526.020. This can carry a penalty of up to 1-5 years in prison.
4. KY is one of the few states that makes it a separate crime to share information obtained while recording illegally. Divulging information obtained through illegal eavesdropping is a separate crime, punishable as a misdemeanor. Ky. Rev. Stat. Ann. § 526.060.
When you combine the entering the building with the placing of the eavesdropping devices then the combination of those two acts can be burglary and would likely be Burglary in the Third Degree which is a Class D felony and like the one above, has a potential sentence of 1-5 years in prison.
511.040 BURGLARY IN THE THIRD DEGREE
(1) A person is guilty of burglary in the third degree when, with the intent to commit a crime, he knowingly enters or remains unlawfully in a building.
(2) Burglary in the third degree is a Class D felony.