Yes, if the payments being rendered are not in accordance with the financial agreement. It is, however, unlikely that they would take such action as it would not be in anyone's best interest.
Unless you have a specific repayment plan that the collection agency agreed to, there is no legal reason that cannot sue the cosigner.
Paying the collection agency will clear up your account much quicker and some creditors will return the payment to you if you send it directly to them. Most creditors sign a contract with a collection agency and cannot discuss the debt with the debtor once they place it with the agency, they must refer all correspondence, communications and payments to the agency for the life of that contract.
No its perfectly legal and if you are still making payments on it, that increases values.
No pay the vendor. If you pay the collection agency they will extract a fee from the payment and you will still owe the vendor
If you own your car or house and are no longer making payments, should you still have insurance on them? Explain why or why not.
Not as long as you continue to make payments on it.
No. The collection agency will validate the amount for you if need be, but the creditor no longer owes you the courtesy of a statement.
No, as they are the legal agent of the original Creditor and the arrangements made with the collection agency are binding on the original Creditor.
Yes
Of course. If it's an unpaid debt, the collection agency owning the debt may try to collect it. And beware, they can track you down no matter what. However, they have to abide by certain rules, which are defined in the Fair Debt Collection Act.
deferment
Not as long as the payments are current and have remained so.