The <PolyStyle>
in your KML is set to 0 if you change it to 1 it will fill. The PolyStyle also lets you set the color and opacity of the polygon.
<Style>
<LineStyle>
<color>ff0000ff</color>
</LineStyle>
<PolyStyle>
<fill>0</fill>
</PolyStyle>
</Style>
For the data in the infowindows, you can add a <name>
and <description>
tag to each Placemark, that will appear in the infowindow. If you have a lot of Polygons, doing that manually might be painful, not sure without looking at your input files why that didn't get generated automatically.