Will my document filed electronically with the court be rejected by the Clerk for writing "L.A" instead of "Los Angeles"?

Hard to say because you don't say where this difference exists on the paperwork. With that said, it will depend on whether the clerk catches it...

Can a family member and is a minor serve legal divorce papers to the defendant?

That is not legal service, not because it was a daughter but because she was under 18. With that said it does not make sense to fight over service...

How do I obtain a written statement from a third party that has information regarding my case?

If you provide a certified copy of the letters you should be able to get information about when it was in his name. Once it was put in his...

Do i have to appear at a deposition at the opposing attorney's office if the name is not my name but the case # is correct?

I agree. The bottom line is if someone is being deposed in a case you are involved in, you should want to be there to see what they say. Never...

Yes you need to amend the summons and serve the new summons and FAC on all defendants.

I would just add, if the trust was changed by your sister with the POA, that would not be appropriate.

Bait-and-switch scheme on my car paint job

Impossible for anyone to say but at least the cost of getting the job redone correctly and possibly loss of use. Depending on the facts, there...

trial by written declaration

Of course it is going to be a problem. You need to walk it into the courthouse ASAP and let the clerk know that the "trial date" is today.

When can I purchase a homeowner's insurance policy after being named the "issue" in a family will?

No. Until you are actually an owner you cannot purchase an insurance policy on the property.

How can I peacefully be coexecutor with step mother of my father’s will ?

Consider getting your own attorney. The attorney will split the statutory fee with her attorney so you have nothing to lose and everything to gain...