What kind of charges could my sister be facing ?

Do not speak to sheriff. First get a good criminal defense atty. NOW!

What are options for getting a sentence reduction or modification if convicted of the wrong crime?

He will have to go through the appeals process and hope the court of appeals agreed with his theory

Can a police officer get formal probation

Of course. It totally depends on the facts and circumstances of the crime, but I don't see why not.

My son who was 15 yrs old was picked up by an 18 yr old at the beginning of summer and has left the state,

Possibly. Maybe you can hire an attorney and a private investigator to work on this with you.

While an out of state overnight house guest at a friends, I was arrested for something I didn't do at a beach nearby

There is a lot wrong with this picture. Get an attorney and fight this case on all fronts.

Can new evidence be presented at an appeal about a person's mental state at the time they committing a crime?

As a general matter, a direct appeal only concerns evidence that was presented in the trial court.

Can i sue someone for assaulting me with a bat

You don't need to wait, but you might be outside the statute of limitations. See an attorney directly ASAP.

Get your husband an attorney. Your merely not wanting to prosecute isn't going to end the case.

If expunge my record can i join law enforcement?

Whether you can join law enforcement is up to them. And you may get expungement, but that' won't likely matter. Law enforcement will see the...

Can my OVI charge become a conviction if I was never actually "arrested"?

The cops don't have to arrest you immediately. If the officer later cites you, you're likely going to be (or already have) been charged and can...