Lessons:
Make sure pathologic is setting the right root URL before boost runs. It seems the very first cron run pathologic still has the old site's information, or rather more likely the page cache or the node cache still has the old information, and these caches must be cleared immediately.
Never, ever have boost set to gather 1,000 pages at once-- it can try to run them all simultaneously and take out your server.
Even when you have boost, don't forget to turn back on the basic performance optimization settings when going live: CSS and JS compression.