Can I use engine oil as chain lubricant?

I’m helping my son write a paper for his eighth-grade class. He chose Chevy as the subject matter, so we’re putting together a section about history. Where did Chevrolet originate?

I recently bought my car from a long-time smoker and there's still some lingering odor. The other day my friend pointed out the roof was stained. I think that's where the smell is coming from. How can I clean the fabric of my car's roof?

I have a financed 2016 Chevy Suburban. I have full-coverage insurance on it now, but once I finish paying off the loan in two months, I'm thinking of switching to liability only to save money. Do you think this is a good idea?