Nobody's Fault but Mine
I really blame only myself for the challenge, but I wish it was easier. I did try the the KML export (and GPSBabel), but it kept saying I had nothing to route. As for Garmin 450 limitations, Garmin told me this was a perfect choice. I guess I don't really understand the track vs. route issue you raised. Aren't tracks where you've been and Routes where you want to go?