Response 2 (late)

1. The range of hues definitely depends on the aesthetic one is pushing for. Usually, a wide range of hues is better just for variety's sake, one doesn't want to get into a habit of using the same hues over and over again, devaluing new work. However, a small range of color can be enormously effective in a piece from a design perspective.
2. A domination of earth colors can create a more naturalistic feel, however it lowers the energy of the viewer, thus creating (in some cases) a more negative aspect of the piece; it may even create a misinterpretation. Adding an intense color will create emphasis on whatever the color represents, drawing the viewers eye towards the splash of vibrance.
3. Wind from the Sea is a much more somber piece, one might even call it creepy. The muted, earthy tones create a feel of death and despair, in contrast to Interior with Book, which is packed with vibrant colors. Whilst Interior with Book does have more intense colors, most of the tones are blue, thus creating an equally somber mood.