Hello Stephen. To fix the icon problem, right click the desktop, go to view in the menu, and options will appear next to original context menu. Select small icons.
For the wallpaper problem, what is the resolution of your screen? What is the resolution of the wallpapers you are using? If you use a wallpaper with a resolution that does not match that of the screen, it will enlarge, shrink, or stretch the wallpaper to fit the screen, which may result in blurriness.