Caught Shoplifting in Pennsylvania - What is Going to Happen

My question involves criminal law for the state of: Pennsylvania

Yesterday, I was caught shoplifting at Boscov's. They took me into LP and took down my information (work, hair color, license, phone number, social security number). Because it was my first offense, and I was cooperative, they did not call the police. They didn't take my picture, they didn't take my fingerprints, they didn't ban me from the store, and they didn't make me sign any papers. They said I would be receiving a civil demand within 2-3 weeks.

1. A lot of people are saying nothing will happen if I don't pay the demand, is this true?
2. I don't want my mom to open the letter before I do, will a PO box fix this problem, although they already took my address?
3. A couple people I know said they were told they would receive a fine and never did, is this likely?
4. How much do these demands generally run?
5. Is it possible to arrange a payment plan?

Please don't tell me how wrong I am or how terrible of a person I am, I feel guilty enough. I made a mistake and I learned from it. I absolutely regret it, and I am sorry if I offend anyone. Thank you for your help.

The stores don't take fingerprints. Even if they report it to the police, you'll just get an order to come in and get fingerprinted/mugshots taken along with the charges. Though chances are if they didn't immediately call the police or say they were reporting it, they aren't.

People here disagree with whether they will pursue the civil demand in court. You can count on them sending MULTIPLE letters however. They'll send them to whatever addresses they have on file. Unless you're going to beat your parents to the mailbox every day they will see a letter from what appears to be a law firm to you. The amount of the demand is $150 PLUS what you stole (even if you gave it back). They are not required to allow you to make payments, but you can certainly ask. These guys are in the fee recovery mode, so I suspect they would.

It's always possible that the store won't send you the demand (note this is NOT a fine, a fine is what would arise from your criminal charges). I wouldn't count on it if the store said they would.