On the quiz, I'd skip it. Nothing you can ask someone in a room predicts what the work looks like on site. A small paid first job does, and it costs you one job instead of a year.
The part I'd change is what happens after they start. Write one page per trade on what finished looks like, with the photos you want at completion. A lot of what gets called a bad crew is a crew nobody told.
Then keep one line per job: crew, callback yes or no, what the fix cost you. Ten jobs in and you'll usually find it isn't a general quality problem, it's one or two crews carrying almost the whole rework number.
Once you have that, use it. Best crews get first pick of the schedule and the jobs that pay. Two crews you can grow beats five you have to inspect.
One more source alongside asking around: the counter staff at your supply houses. They see who buys the right material and who returns half of it.
