I can't quite make out of the author is in middle school or maybe a very immature high school freshman.

Keep up the writing exercises young man. Next time a bit of fact checking might be in order though. Pro tip? Howard Zen isn't actually a historian. More a creative writer, really. Using him as your only source on US history makes you look foolish. But keep trying, kiddo.

Your main contention- advising people illegally living here to avoid breaking yet more laws- is fine. Suggesting they go home and lawfully apply for a visa would be better still.

Centet, living in the US as a non-citizen, or even without authorization, is not a crime. In WA state, neither is using marijuana. Also, your last sentence betrays your complete lack of knowledge on this subject.

Marijuana is illegal under federal law, even in Oz.