Booking info/pictures after dismissal

Your question is confusing. Has the arrest record already been sealed or are you trying to get it sealed? It's also unclear why you are concerned...

If a charge is dismissed because elements/legal definition not met can file be sealed??

Mr. Finnecy is correct. Get a lawyer to explore options under 851.8.

I am on probation, i.e. NOT in custody, after doing time in state prison. Am I "currently serving a sentence" now on probation?

If you did time in prison you are now either on parole or post-release community supervision, not probation. It's not clear what you are seeking...

The wife of a DEA agent, stated as a witness on record that an altercation had accrued between a husband and wife

I would talk to a lawyer before talking to some government "good ol' boys."

If I am eligible for both resentencing/reduction under either Prop 47 or PC 17b, is one better?

It really depends on the circumstances and the details of your case. Consult lawyer.

Definition of Criminal Threat

As you point out, penal code section 422 turns on the perception of the listener, not on the intent of the speaker. At the federal level, this...

Do we need a lawyer?

You need two lawyers. Each of you needs your own.

As Mr. Broughton points out, unless you are in custody, the DA has up to the date of the Statute of Limitations to file charges. The SOL is one...

Each of you needs his own lawyer in this case. This will not "go away" on its own. You each need a lawyer to fight for you. Retain them...

Can the detective say no to a return of property request?

My colleagues have explained his comprehensively. As long as the items are not illicit, illegal, or contraband, your lawyer can petition the court...