You might be able to disable those using PermissionsEx.
I stopped the kill chain by removing scoreboard data, and now I can roam my world.
On the Options screen, click Multiplayer Settings.
Do you know what is going on? You can follow the design development of the subreddit at.
It will be better solution, if it won't block everything, but well, I'm unable to test it for now.
I've tried MCEdit, but it didn't work.