Can a collection agency call the county in which I live and have a warrant issued for my arrest for non-payment?
You cannot be threatened with criminal action for a past due debt. The fact is that people do not go to jail for owing money. The exception being if you had committed a fraud of some sort in obtaining the funds, etc; that would be a crime. For example, if you borrowed money from someone with no intention of repaying them back. Other than that, neither a debt collector or creditor may threaten you with criminal charges. If they do you could actually sue them. Addtionally, they can not harass or otherwise intimidate you. It's the law and is called the "Fair Debt Collections Practices Act" (FDCPA).
That having been said, this doesn't mean that you don't owe the money. Just be careful in how you set-up repayment plan (specifically, just what information that you give them - especially banking information).
If you feel that your rights have been violated you can contact your state's attroeny general's office or department of consume affairs. You can also contact an attoreny regarding the crimina threat; tjere are attorneys who specialize in representinhg victims of illegal debt collection practices.