I've completed an example page the demos most of the features we'll need. I've rendered everything as vectors on a single layer, and abandoned the import of KML (see my previous post).
Arrays for lines and polygons are currently static and are embedded in the page itself.
Next task is to determine the best way of generating them and passing them via ajax to the page. I'm looking in to the options: GeoJSON, GML, GeoRSS and Well Known Text.