Because you are married, you cannot be treated as single. You can file a joint return, or you can opt to file as “married filing separately.” However, if spouses live apart and meet certain tests, one may qualify to file as head of household instead of married filing separately. To do this, you must have a qualifying person live with you (or a dependent parent even if not living with you); a spouse is not a qualifying person.
Debt on which a person is not personally liable. In case of nonpayment, the creditor must foreclose on property securing the debt. At-risk rules generally bar losses where there is nonrecourse financing, but an exception applies to certain nonrecourse financing for real estate.