You need to talk to an immigration attorney about what your best course of action is, given the convictions you picked up.
These answers are not intended nor shall it be deemed to be the rendering of legal advise, they are given based on the information provided which is insufficient to give meaningful advise. These answers shall not be construed as part of the creation of an attorney-client relationship, nor shall it impose an obligation on the part of the attorney to respond to further inquiry. The Questioner has responsibility of obtaining legal advise from an attorney and is urged to do so.
Unfortunately your problem is a hybrid that requires both Immigration Counsel and a Criminal Defense Attorney. You will have to speak to an Immigration Attorney to find out how your misdemeanors will affect you. The good news is you are not in removal yet so that bodes well for you.
You have nothing to lose by applying for an expungement on the 96 case now. It's old and the worst that would happen is it would be denied. You should do it and then focus your energy on your other two cases.
With respect to the DUI's, you do actually have remedies. While it's difficult to get a court to terminate probation early on a 2nd DUI, it can be done. You have to have a very compelling reason and immigration is a compelling reason. If you can get early termination of probation, they you would technically be entitled to expunge all of your convictions now.
I can't render an opinion as to whether getting all this relief will be a bullet proof solution to your immigration worries, but if you have completed the terms of your probation, meaning you owe the court nothing else other than the year of probation you can apply. Its a complex noticed motion requiring a hearing and you would want an attorney to do this for you. If we can be of assistance we are happy to give you a free consult.