I've lived in the Greenbelt area (College Park) area for a long time, ntil 2 months ago. I can't think of many areas of Greenbelt where I would reccomend someone to live. The north end of College Park could work better than Greenbelt. Probably only locals know it, but there is a walkway to the Greenbelt Metro to the College Park side of the station. On the Greenbelt side it doesn't look safe to walk on the road there to get to the station. Also the apartments nearby get a lot of police calls. College Park is right on 95/495 and pretty close to both 95 and the Baltimore-Washington Parkway. This mornings paper had a story on a home invasion in that area. The story was surprising because it is pretty rare there.

Another nearby place that beats Greenbelt is Beltsvile. It is betweeen Laurel and College Park and right next to Greenbelt. With the big USDA farms there it kinda feels more small town than urban though.

If it were me, I would go for the Columbia area. Based on your description, I would say somewhere in DC, that is safe, would fit better.