The defendant's compensation is based on the ability to reduce the punishment, so we must think of ways from this perspective. For example, obtaining compensation, issuing a letter of understanding, etc.
Even if there is no letter of understanding, he should still compensate and the court will impose a sentence. However, it is not as quick and costly as negotiating compensation. Therefore, it is recommended to negotiate a solution.
As for the last question, I have already answered it before. If the injured person refuses to accept the crime and actively pursues his criminal responsibility, the possibility of a suspended sentence will be even smaller.
I hope my answer can help you. If you are still unclear, you can find me through the link below.
Your friend, Lawyer Zhao Li of China Criminal Defense Network