Police entered into an agreement to protect Mo and Jade and that continues after Mo's death if there is a reason to fear reprisals. It is likely that the protection offered Jade has been substantially reduced. After all, she agreed to be interviewed for this book when it could have put her life in peril if someone is still out there looking to settle a score with Mo. But I think she is still under the obligation of protection, but protection is only provided on an as needed basis. That said, I doubt if police are handing out her number.
Most Canadian writers can barely afford to do research for the books they write.
I would be awfully surprised if I made any money off this book. My last book sold 6,000 copies and I would have had to sell another 7,000 to start collecting any royalties. So it is not an issue with me. But the point you raise is a good one. We feel great empathy toward the families of the victims in this case and we met many of them and are torn by their stories.