2. Li Yi's act of selling necklaces is invalid and the court should support it. Li Yi 13-year-old people with incomplete civil capacity can only engage in civil legal acts equivalent to their ability and intelligence. The effect of mass sale of the subject matter is to be determined (determined by its guardian). If the jewelry store notifies angel lee for two months, it will be deemed as the default that the behavior is effective.
Li Bing enjoys the copyright. He used the ownership of his works to pay off his debts. Since copyright and ownership pay off their debts, Fan enjoys ownership and can be used for exhibitions.
Li Jia's request for compensation for furniture damage can be supported by the court. Although Kim is managing for free, China's civil law adopts "no-fault liability", but due to the burst of his own water pipe, Kim must have the responsibility of management, so he should pay compensation.
5. You can't ask for re-guarantee because the defects in the subject matter are caused by improper management, and the guarantee effectiveness of the subject matter is not lost due to the fault of the manager.
This topic is very good, involving the general theory of civil law, property rights and creditor's rights. I can't guarantee that I did it right, but it's for your reference only.