Well, I completed and returned the code challenge about 2am this morning. I actually had the code challenge done about midnight and spent the next hour or so working on a few test scenarios and filling in a few places I forgot to add documentation comments. Then I spent a little time trying to come up with appropriate and professional sounding answers for the series of questions. Honestly, those questions can be harder to answer than the code challenge.
The job recruiter said the company has a test suite they run submissions through, so now I wait.