Law - Why have imports, Why limit imports

Law

https://youtu.be/fhp5L76OEPA

1. Why have imports?
2. Why limit imports?
3. How would a city or region that imported less benefit from limiting imports?
4. What types of products could be more locally produced? Why? How?
5. In what other areas would self-reliance be a good idea? (other "essentials")
6. What are local examples of self-reliance or import substitution? (farmers' markets, local fairs with local products)
7. Does self-reliance mean no trade?
8. In what ways do current laws/regulations make it difficult for businesses to stay local (not export) their labor/resources/businesses? Be Specific.