1. If the lending company has a subsidiary company here and they have collecting functions, then it is possible that your outstanding debt can still be collected.
2. Referring to the above answer, a case can be filed against you if they have representatives here.
3. Since a collection of sum of money is a civil case and is not criminal, you cannot be imprisoned for such.
4. It is possible if a case was filed against you, but the NBI usually tracks criminal cases if I am not mistaken.
5. Yes, since at this point, we don't know yet if a case is filed against you. Since there are no records of any sort that would alert the airport authorities, you should still be able to travel freely.