Can witnesses testimony be valid if ....

Huh...this is too confusing to follow.

Blew 3 times over and wondering if it's possible to get the case dropped

That type of reading makes it difficult to get the charge reduced. Hire a good attorney to avoid jail if possible!

What are the chances someone on probation for a felony go to prison for bigamy?

It sounds very possible.

I doubt anything will be mailed to you.

That would be unusual. It's only 1 offense and it's not a felony.

Am I likely to receive a pardon of one offense in one state when I have 2 other convictions in another?

That sounds like a stretch for a pardon.

I have have just got arrested for retail theft in Philadelphia. What are the processes I need to go though before my hearing?

Get your parents involved. Get an attorney!

Class 3 aggravated identity threft

Prison is unlikely for a 1st offense.

Does this sound like a good defense, and how would I word it? Now sure how to fight this now.

You've asked this before. It makes no sense that the judge would allow them to re-open. That being said, it will still be difficult to establish...

Where can I get the information on the terms of my plea?

Go to the clerk of the court.