You will definitely get locked up if you fail to attend the Informal Admin. hearing. At least, with a hearing, you stand a chance of avoiding jail. Speak with local counsel and make sure you attend the hearing.
Not necessarily; however, counsel will be able to better advise you once you provide him/her with more details concerning the circumstances surrounding the hearing. It seems unwise to skip the hearing and ensure that you'll be arrested when your attendance may avoid it.