Beautiful work Garris. You've been getting some great light and skies to work with, especially on the Capitol Building shot.
Your ghosting and spotting, I'll take a stab at. First I'd say try using a lens hood for the spotting, theres no way to get rid of ghosting-movement when the lens is open for a period-maybe try to use that to your advantage. If you bring down the ISO a bit you also will reduce the spotting-at least thats my experience. I hadnt thought of stopping down the aperature but that might also work. Obviously you're using a tripod so a longer exposure wont be an issue. I've done some night work and have found that the angle you take in reference to the major light source also affects the amount of spotting you'll get. Good Luck with solving this one, although from your results you dont need too much. Send me a PM some time and let me know how it goes.