Hi there! I'm sorry to hear about all of the trouble with this app!
As Scott mentions, you have to be very careful about not having an app editor open in more than one tab/window. We are working on a feature called multiplayer that will soon allow you to have multiple people editing the same app 
Cloned apps don't typically have a lot of history since the history prior to duplicating the app won't be accessible in the new copy. That said, I'd recommend trying to step back in the history a little bit, as described in #4 here to see if that gets your app into a better state 
