Can't fit all of the defendants in the summons pdf?

You will need to continue the names on an attachment, the court clerk's office may have a form available for that use

Can I serve companies with a P O Box number via certified mail?

Also, if the companies are registered with the Secretary of State there will be a registered agent for service of process listed.

What form is used to vacate a default?

In addition to the above answer, you could proceed with a "prove up" hearing based on the default you already have in place. You would need to...

Transfer cost to a county where there is an open case

There should not be a new "filing fee" but there may be some other fee involved in the transfer, ask the clerk of the court in the county where the...

Can you use papers gotten in discovery from one legal proceeding and use it in another lawsuit ?

Typically, if it is relevant and properly authenticated it would warrant at least consideration by the judge for use as evidence, depends on the...

Certainly a person is entitled to have an attorney at deposition if desired. I would suspend any deposition if a witness requested counsel.

I can sue tmobile without a lawyer? and do it myself

Seems like it was their fault, you could pursue in small calims - but be wary of arbitration clauses or jurisdiction clauses if you have a written...

To set aside declaration of paternity

Depends on how the declaration was entered, was it by default? This is very important, you need to see an attorney right away

Multi-state/country document discovery requests - what to expect

Since California is the jurisdiction where the lawsuit is filed, you can demand production here of the originals, the other side could file a...

No Intention to take a default

Yes, you need to respond unless you have a written extension to respond or the matter is settled and a dismissal is filed