What are the chances of me losing a 500k rear end lawsuit?

Report the lawsuit to your insurance company for them to defend the case. Make sure your insurance company settles the case.

Yes, that is Malpractice. The issue in California are the laws that protect doctors and limit the amount that can be required making such cases...

Serving papers?

If you are referring to service of a summons and complaint, there are other methods of service, including substituted service and service by court...

Is it legal for a surgeon to remove a bone (nasal spine) for no medical or cosmetic reason w/out discussing it with us first?

A doctor may not do anything for which there was not informed consent.

Can additional parties be added when P files an Amended Complaint or It has to be done thru a separate motion?

Unless the Court gave permission to add parties, you should file a motion to amend to add parties.

An amendment to the complaint does not have to have the attachments but an amended complaint should. For ease of the Court and the parties it is...

Is my contract valid ?

If the terms of the bid were changed (did the bid specifically incorporate the picture), then you are not bound by your bid.

Does the appeal form APP-012 for extension have to be original ink to be able to file it?

Yes a copy is sufficient. They will let you know if they need original.

Is there anything I can do after someone has already been released due to lack of evidence?

You can bring a Civil Lawsuit for your children.

Diversity?

Diversity is determined at the time the lawsuit is filed. But you may be able to file in state court and wait for defendant to file for removal.