In the State of NC you must be separated for a year before initiating the divorce proceedings. (FWIW, Any resumption of living together during that time will reset the clock.) Separation is not a formally filed process, it begins the moment you move out with the intention of remaining separate. Usually an affidavit (like the one on the papers when you file for the divorce) is sufficient to demonstrate separate and apart, however, if she challenges, make sure you have your utility bills or rental contract available. If you wish to keep the residence, then she will have to move out whether it be voluntarily or through jail. If you choose to move out and your name is still on the lease/mortgage, you’ll still be liable for any payments.
FWIW, and Ryan will have to confirm this, but if your concern about your STBX’s undisclosed debt has to do with you being held liable in the divorce process for it, I don’t think it matters. The debt was incurred as an individual prior to marriage and wasn’t shared so therefore it is hers and hers alone. The only issue that it might present is during equitable distribution where you make take on more of the actual marital debt to offset, however, there are arguments to be made (like the lack of disclosure) to prevent that from happening.
As far as the accident and liability goes, it is possible that you may be liable under the family purpose doctrine, however that is somewhat limited in this state. If you knew that she was an irresponsible driver and she had still had your permission to use the vehicle, you may be held accountable. However, if she had been a normal driver and you had no knowledge of any driving issues, then you shouldn’t be, although they may still file something against you that you’ll have to refute in court. Sorry. You might want to read this for a little info: http://caselaw.findlaw.com/nc-court-of-appeals/1341707.html
NOT AN ATTORNEY