If you set the Wind arrow in scale control to  the length of each wind arrow will be the distance you will travel in one hour.
The two Wind filters options allow you to show or hide wind data according to how strong the wind is. If you set the show tws >= to say  then all the winds less then 5 knots will be blanked out on the chart. This is useful for highlighting holes in the wind that you need to avoid.
The wind values shown on the chart are those taken from the Grib files, which are at 1° Lat and Long intervals only. Remember that the VORG uses interpolated winds, so both the wind speed and direction vary linearly between these 1° points. You can see this as you move the Ruler , Route , and Track tools over the chart.
Every time you download weather from any of the sources, the downloaded weather is contained in a weather "grid", and is added to list of grids in the window. The grids are automatically named - the name usually (but not always) identifies the area covered, a time-stamp and where it came from.
If you tick the overwrite previous wind grid box, a subsequent download will overwrite an exsting grid from the same source and for the same area.