There are lots of explosions in Of Great Price, but I think that each one of them is more or less canonical. I know I had to make up locations for a few of the battles, but I think that JKR laid the groundwork for each of them Of course, I also think she laid the groundwork for Remus/Sirius, so I could be a little over-reaching ;-)

And that sentence is perfectly fine compared to many of the horrors I see at work.