Total Number of Treats Needed to Get Everything!

I too have managed to buy all the listed items with treats, and am building up a sizeable store of seemingly useless treats. Does anyone have an update on what will happen at the end of October?

Will unused treats simply disappear?
Will Heck House disappear?
What will happen to the two cemeteries?

Also, having saved like mad to get the Burns monster, what does he actually do????