If you are on anothers property without permission and the landowner wants to pursue charges for trespassing and sign a complaint then any Sheriff, State Trooper, or local Police Officer will arrest based on the land owner's complaint. Penal Law Section 145.05....A person is guilty of trespass when he knowingly enters or remains unlawfully in or upon premises. Premises bieng defined as "any building or real property". Now under the penal law as you said if this land is unimproved, unused neither fenced or otherwise enclosed to keep out intruders or conspicuously posted it would be thier word against yours and all they would have to do is articulate how they use the land. If it contains an outbuilding or a food plot or plantings is it considered improved? Now I would feel uncomfortable signing the complaint myself which is why the landowner would be signing the complaint, and would try to encourage the landowner to just let a warning be sufficient. Too many gray areas and the benefit of the doubt would be with the landowner. Your research is pretty good but until you know all the variables including landowners interpretation of the land's use, it's best to get permission. Like I said until the landowner complains, your are technically ok. But get an anti-hunter land owner and I can almost bet they will come up with a use or improvementfor the land. There are many ways to interpret the law and sometimes it reads like stereo instructions.