The .GPX file format is a kind of de facto standard format for storing route information on GPS devices, so any routing website that can't handle it is not going to be much use. Google Earth uses a different format, .KML. Google them and you'll get an idea of what they do.
I think that changing the activity from cycle to something else affects the energy burn calculation. I haven't checked it but I assume if you set it to Drive you shouldn't get much credit!
