You are wise to use the Metro. I live here and almost never drive downtown because I don't have the patience and you never know what will happen to shut traffic down.

If you are staying in Georgetown there are lots and lots of different restaurants to eat at. This is actually one of the best areas in town for that, so your problem will be deciding where to eat

The easiest (but not the shortest) route from Baltimore to DC, is go down 95 and take 495 (into Virginia). Just make SURE that you do not travel during rush hour (495 is REALLY bd at the best of times).

You can bring in cameras and flashes into all the museums, so that is not a problem. I would also recommend getting the tickets for Tia Shan now, because they go really quickly.

I suppose that you could walk across the bridge, but that could be a long walk... you would be better off taking the Metro across and then walking from there.

The one thing to know about travelling in DC, is that cabs are not that expensive. They are paid on the grid system, so it is a flat rate within each grid. Then once you pass over into another grid, there is an increase. But they do not charge by the mile or the minute, so taking a cab might be an option for you.

If you would like I will PM my home and work phone number for you. (I work down by the Mall)