You won't have any problems. The Reagan Building is virtually attached to the Federal Triangle Metro station, so you have both the Orange and Blue Lines available to get you to work. Looking to the west (which is the more upscale side of town), the train takes 30 minutes to Federal Triangle from Vienna, and 35 minutes from Franconia/Springfield. The basic start point for 2/2 apartments in the area is around $1500, so you should have plenty of room to pick and choose what you like and still stay within your budget. There are townhouse and condo options as well as SFH rentals, many of which would fit into the plan as well. Exactly where to look would depend I think on your lifestyle preferences. Out to Ballston on the Orange Line is basically high-density in nature. From East Falls Church on out, you have more of an SFH-dominated upscale suburban set up. Along the Blue Line, you've again got high-rise, high density through Pentagon City and Crystal City, then the city of Alexandria (which is still dense but has some lovely neighborhoods) and then on out to Franconia/Springfield/Kingstowne which is more upscale suburban again.
You could also go the Red Line route and use Metro Center as your stop. That would leave you a 10-12 minute walk to get to the office. It's downhill in the morning, though. That would put a lot of Montgomery County into play. Taxes and insurance are a little higher out that way, but there are all manner of environments to choose from there as well. It's 35 minutes to Metro Center from Shady Grove, and 25-30 minutes from Glenmont.
Education-wise, George Mason University is in Fairfax VA, accessible via shuttle from the Vienna Metro station. George Washington University is at Foggy Bottom (Orange & Blue) , and Georgetown is just across the bridge (via free shuttle) from Rosslyn (Orange & Blue). The University of Maryland is in College Park, which is on the Green Line. American University is about a mile from the Tenleytown station on the Red Line. There is regular bus service throughout the day.
As for diversity, there is tons of it. The DC area has multiple well-established cultures, none of which is truly dominant. That diversity tends to diminish as you move further away from the city though. By the time you reach the outer suburbs (most of which have been developed since 1990), it's nothing more than average. As an imperfect rule of thumb, what's inside the Beltway (I-495) is the inner suburbs, what's outside the Beltway but inside the extents of the Metro system is the middle suburbs, and beyond that is the outer suburbs.
So based on the info you posted, that's a start at things. I don't think you'll have any problems at all. If you want to look around at some of the residential options available at the moment, trusty old Craig's List is an option, and so is a site called Military-by-Owner. You don't have to be military to use it, and a lot of people around here do...
craigslist: washington, DC classifieds for jobs, apartments, personals, for sale, services, community, and events
MilitarybyOwner.com - Real Estate near U.S. Military Bases
To check out the Metro system and what it means to your commuting (and therefore living) options, click the Maps & Stations link on their home page...
Washington Metropolitan Area Transit Authority