"Buy someone insurance, then act" is a dead end from the start in law: you get not one cent, and the crime is intentional homicide plus insurance fraud with the sentences combined

In plain words

All four doors are closed. Buying a death-benefit insurance policy on someone behind their family's back makes the contract void. If the policyholder intentionally causes the insured's death, the insurer does not pay. Anyone who intentionally kills the person from whom they would inherit loses the right of inheritance. The Criminal Law (刑法) also lists this kind of insurance fraud as a separate item, with sentences combined with that for intentional homicide, up to death. You do not get one cent.