I am not sure what you want to do an actual pic of the house is a much better place for us to start.

I think a transom is a great idea . Do you plan to cover it in siding like the rest of the house or do you have something else in mind? On this style I think anything too dark will make it look harsh and possibly give the impression it's a business. I would use more earthy tones.

Transom is good. You have narrow and longish short house it seems to work with. But you need to stay darkish grey on your siding and verticle grooved to appear you have a taller building.

If you are thinking new roof, go a warm lighter natural on a metal roofing. Metal roofing and dark siding is stunning waterside and with stone. My house is also on the water but the front close to the road so I did my homework before settling on my materials. This will make up for what you lack in front facing space and enhance your entrance in any colour.

A few colourful shrubs and ornamental grasses make closeness to the road a non-issue visually. I think your style is more Asian modern so take a look at the architectural benefits of varied grasses that will come up each year and set them in river rock stones which are also surprisingly varied.