-For your question 1 and 2, you can do it in one line of code as you can see below:
myLayer.ZoomLevelSet.ZoomLevel01.DefaultAreaStyle = AreaStyles.CreateSimpleAreaStyle(GeoColor.StandardColors.Transparent, GeoColor.StandardColors.Green, 3);
Here, we set the fill color to transparent and the border to green with a width of 3.
-For your question 3, what you will need is a ClassBreakStyle. You can find an example on how to use this style, in "Draw Thematic Features" in the section "Styles" of the How Do I samples that come with the Map Suite Web Edition product. In each ClassBreak, you can use an AreaStyle as described above.