Oh my. gosh. FABULOUS. I love the theories!!! Hmm... well, maybe HWWB enjoys the power of knowing he can really throw Harry for a loop sometime/manipulate him against others in the evil realms to wipe out his opponents. Rather a lame theory if I'm allowed to criticise myself given the fact that he couldn't necessarily TRULY know how Harry would turn out. this also does, however, make me wonder if possibly Kemmler/DuMorne was controlling HWWB and using him to draw out Harry's power and prowess and train him by making him fight. It certainly would fit with K/DM's training methods, and perhaps K/DM was still hoping to turn him at some point (a possibly more valid, albeit outlandish theory)

Maybe K/Dm wants to take over Harry's body when he's strong enough? Maybe the whole point of the Black Council is to throw obstacles at Harry to make him stronger. When the BAT comes around, K/DM will try to possess Harry and become the most powerful wizard in the world. So they don't want to kill him, just push him just enough to become a worthy vessel for K/DM. Of course, that's just pure speculation