Legal Question in Constitutional Law in Georgia

It sounds as though either the ICE agent missed part of the class or something was lost in translation. Your question seems based on a false premise. Keep in mind that a federal agent has no business arresting people for a state offense, such as driving without a license, regardless whether the person's entry into the U.S. was lawful. Assault, likewise, is typically a state law offense. If an American (if, by that, you mean U.S. citizen, as all South Americans and Central Americans are also American) committed a state offense, the federal agent would not arrest them.

It is simply not true at all that anyone, regardless of citizenship or lawfulness of entry into the United States, is "exempt" from being arrested for a crime based on being in the U.S. since childhood, going to high school or being in the military. Total hogwash. If an ICE agent told you otherwise, I suggest you report it to the ICE agent's superiors.

ICE agents do not have universal law-enforcement authority. They only enforce federal immigration and customs laws. The crimes you list do not violate those particular laws (with narrow exceptions, such as assaulting or fleeing arrest by an ICE officer).

You're right that American citizens and legal aliens would be arrested for these crimes. But they wouldn't be arrested by the ICE. They would be arrested by local police departments, the FBI, or some other law-enforcement agency with appropriate jurisdiction. Those same agencies would arrest illegal aliens for committing the same crimes.

The policy you describe (which I presume is real, though I haven't verified it) thus does not treat illegal aliens more favorably than Americans or legal aliens. None of them would be subject to arrest by the ICE for these crimes, but all would be subject to arrest by other departments and agencies.