Is there a way to use the search results as input data in a macro or Lua script? Are APIs available?

There currently isn't a way to output the search results. I'm afraid there is no API other then calling the functions yourself or outputting the data from the tables/arrays generated. You can view all the information for BagSync though from the WTF folder.

C:\your wow installation_retail\WTF\Account Name\SavedVariables\BagSync.lua