Well... i never tried butane extraction myself, but i know well the physics/chemistry behind it, and im sure the vaped weed wont make the process more dangerous than un-vaped weed. So, the outcome 3 is not possible. The chances of an accidental explosion are the same using vaped or un-vaped weed.

I know people use to cook with the vape leftovers, so there is still THC in it. And if there is THC, you can get some working honey oil. Of course it will be weaker than if you used un-vaped weed, but maybe it still will be very good... the surest way to know is to try. You have almost nothing to lose (maybe some butane) and a lot to win (lots of honey oil), and thats why i suggest you to try it. Im almost sure the results will be good enough.

So, good luck, and tell us how it was! :thumbsup: