Many data sets hosted on Socrata don't allow access via the normal api - only a zip file of the full data set, along with some possible attachments, is available. Is there any way to download this full data set via the SODA api? I'd like to, for example, only download the data set if the metadata that I can see via the discovery api says that the data set has been updated.
Unfortunately not. Those are special datasets that are hosted as downloadable assets rather than as data in the Socrata API, so you'll need to fetch it from the asset's landing page. If you need to, you should be able to screen scrape it, however.