Washington should strictly be a federal capital. It should not be a city-state. And it should be moved in the middle of the country more, like in south-central IL or west-central TN.
Yes, and Congress should be housed in a barracks and fed in a cafeteria.
No restaurants or bars allowed. Have a dormitory for those who have a reason to meet with Congress. No fancy hotels for lobbyists.
Give our elected officials as little reason as possible to stick around. Let them telecommute like everybody else.