Nice wood closeup, thanks. Here is a fun site full of wood samples with different stains: http://walzcraft.com/cinnamon-w-6-36569/
There are any number of wood nick coverups on the market. I like Howard's Restor A Finish.
For new carpet, new installers should remove the old layers to make it a much sturdier and safer staircase. Too much uneven old carpet gets to be a safety hazard. For carpet color, I suggest getting a teaspoon of dirt from the yard, then choosing something similar in a medium, not dark, color unless you run a no-shoes household, in which case you could go with a lighter medium tan or darkish beige.
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Furniture arrangement and fireplace
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