The mediator caused damages to my son

Huh? I don't get what your question is. Please rephrase.

Is there a document my son's father can sign that says when or if the time comes he will agree to me changing my sons last name?

If you have an open case, you can create a stipulation and order re name change. Family court forms can change twice a year so it is better to get...

My daughter passed n my grandson whom she had by a one night stand was taken by his father n won't let me n siblings see him.

I concur with my colleague. Alternatively, you could patch things up with the father.

Can I do a emergency court hearing and can I ask for 50/50 custody

Emergency means threat of imminent threat of physical harm or threat of irreparable injury.

For what time period am I entitled to retroactive rental income from community properties?

From the date of separation to date of trial.

I concur with my colleague. Has your sister asked her not to contact her? What is the nature of the contact?

If the defended in divorce decree doesn't exist how is divorce valid?

I concur with my colleagues. Do you not want to be divorced from him?

What to do when child runs away on my court ordered weekend?

Contempts are not easy for a pro per litigant. If you go that direction, I strongly suggest you hire an experienced family law attorney. Sounds...

If I am married in Israel but live in California, can my wife divorce me without my consent?

I concur with my colleagues. No consent is required for a ca divorce.

Illegal? No. Should it happen? No. Best to get an order for no corporal punishment by 3rd parties.