The other contributing factor to the noise might be that Bachmann F unit... Not exactly the Cadillac of N Scale.
(I've got a pile of them in the "Box of Time" under the layout, so don't sweat it, we all started somewhere.)
That's a neat track plan you've come up with. Is it from a publication or did you create that yourself? I also like the approach of scratch bashing the bridge. But you might want to spend some time looking at proto photos to see if you've gotten as close to the look as you can. One other obvious note, if you've got a port between those two bridges, at least one of them needs to be a draw bridge to let the boats in and out!
As for the port/coal mine design, the best recommendation is always to see what happens out there in nature. Use the aerial views on Google or Bing maps with reckless abandon. (You can find railroads that are abandoned, too!)
Welcome to the Railwire, and to N scale model railroading. We'll look forward to more postings on your progress.
Lee
