Usually, when confronted with a regex problem, I try to simplify both the pattern and the input until I get something that works and then build back up from there.
In this case, though, I'm going to suggest you'd be better off abandoning regex entirely. The example data is in CSV format, and there are CSV parsers—like csvkit and Miller, both of which can be installed through Homebrew—that you can use to extract the information. You could even use them to convert the CSV into a JSON file and then do all the processing in Keyboard Maestro.