Lyle,
1). currently we don’t have an API to support this directly, that’s a great feature though and we will consider to add it in the next release. For now, a solution (with bad performance though) is looping the locations to find every driving time from the address, and select the one with minimum cost as the closest location.
2). We support defining the service area based on the driving time or distance around a location, you can refer to the sample “Samples / ServiceAreaDefinition” installed with the product for details. I think that’s exactly what you want.
Thanks,
Ben