Not sure how I feel about a heist-but-not-really book of heists. Just make a book for murderhobos who want to rip people off. Not everything needs to be church group-approved.
I echo the thoughts about there being a missed opportunity in having dragons running a thieves guild. And, again, even good dragons like their hoards -- just let the thieves steal stuff in return for the dragons getting a cut. Not every adventure needs to be about saving the day.
So, for people who've got the book, are there any new monsters, magic items, etc., that would be worth buying piecemeal on DDB?