I regularly use four different dash styles from the dropdown list.  Is there an easy way to highlight them or move to one place to avoid mistakes in picking the right one each time?

How is this?

Make example lines with different dashes and put them aside like items on a map legend.

Now draw your lines with regular strokes - then copy one example line from the legend - select every line you want to have that dashed appearance and go Edit->Paste->Paste Style or its hot keys: cmd+C and shift+cmd+V.

Thanks Polygon.  Thats definitely an improvement on what I was doing previously.