回复：you get nothing if you don't buy rental insurance

You are mistaken. Your own rental insurance dose not cover your own bodily injury, no matter what the cause is. Your own rental insurance covers the personal property owned or used by you, and other people's bodily injury or property damage you are legally liable to pay for. In other words, if someone gets hurt because of your negligence, and you are legally liable for his/her injury, then your rental insurance will pay for the claim.