In some states, you can gain access to a safe deposit box by filing a petition to the court. You don't necessarily have to probate the case. Call the probate court in your county and ask if this is possible. Good luck.
In Georgia, where I practice, the test is where the decedent was domiciled at the date of death. Domicile refers to the place where one lives with the intent to stay and not return to another state. It sounds like your ex-husband's domicile was California, but you should check with an attorney in your state. If it is a question of intent, then it will probably be fact-based.
It depends on your agreement with your attorney. I typically prepare all documents that are to be filed with the court so that all my client has to do is sign them. Don't wonder. Check with your attorney so there are no miscommunications. Good luck.
Thank you for your question. While this may have been an error that approaches malpractice, in order for you to have an actionable case, you child must have suffered some damage that was caused by the malpractice. Fortuantaely, it dosen't appear from your question that your child was injured. This is great news. You could contact the pharmacy and let them know of the error or contact the state board overseeing pharmacies and file a complaint. Good luck.