Vacation accruals unpaid

It's your employer's duty to keep this information, whether or not it appeared on your pay stub. I think you do have a wage claim if you can prove...

How long can my former employer hold my final expense check after I leave the company in California?

There is technically no time limit, but the employer is required to reimburse you for all expenses under California Labor Code section 2802.

Yes, only the court and licensed lawyers can issue subpoenas.

I don't think a deadline date to file a motion to compel is triggered yet because the deposition has not occurred. I agree with the two comments...

I am an in pro per Plaintiff in a civil litigation suit and have been counter-sued.

You don't need to file and serve a Summons in a Cross-Complaint if no new parties are added. If you were already the plaintiff in the underlying...