Army OCS disqualifications?

I have been thinking about joing the Army for a few years now and have recently spoken with a recruiter. My education consists of a B.S. in Journalism/Public Relations/Advertising (GPA 2.9). When I was 20 yrs old I got in trouble TWICE for having possession of alcohol (M.I.P). My question is would this disqualify me from beening able to get into OCS. I have only two other minor traffic tickets. I have read that waivers can be granted. Would I be able to get a waiver for an MIP? I was told by the recruiter that there is a chance but it is slim that I would be accepted. Is this true even if the two incidents happened over four years ago? I also was told that if I enlisted I could choose my job and after 6 months apply for ocs and have a much better chance of getting into ocs. If I went this route would I be able to become an officer in the field that I selected when I enlisted and would I be able to apply to OCS in 6 months? Any help would be great!