Hi Jessica,
Re wood decks, you should look at some real ones, they are usually teak, and they are of fairly uniform color.
I might consider sanding the raised lines off the plastic decks and scribing the lines between the planks lightly with a pointed scribe.
After you paint the teak color, a wash of black oil paint thinned with turpentine would collect in the scribed lines and look like black caulking.
A coat of flat coat to seal it would finish it. (you might want to practice the technique on a piece of scrap plastic sheet before you try it on the model, but I have used it before to good effect-)
Remember the problem with using real wood in a 1/350th kit is the grain.
The grain is still 1:1 and on a 1/350th scale model, it may look huge by compairason with the other details.
Jim :pint: