Simple DUI's are not necessarily "crimes involving moral turpitude," which can be deportable offenses, however, multiple and/or aggravated DUI's can rise to the level of a CIMT. Please consult with an immigration attorney as soon as possible to discuss your husband's case.
DUIs generally do not give rise to inadmissibility to the United States, however, you may be questioned and detained regarding any arrests upon return to the US. Also, you must make sure that you are not violating your probation by leaving the country.
Even if the calculation is correct that the 5 years are up, you may still have options to pursue your permanent resident status through an offer of employment from your company. You should consult with a qualified immigration attorney as soon as possible if you are not satisfied with the information you are getting from your company.
Generally, if you are seeing approval of an immigrant visa petition based on a spousal relationship, you must satisfy the USCIS, by a preponderance of the evidence, that you entered the marriage in good faith. If you entered into the marriage AFTER the commencement of removal proceedings, however, the burden of proof is "clear and convincing" evidence. The Immigration Judge does not have jurisdiction over the visa petition, but does have jurisdiction over any application for adjustment of...