I really do love what Ember brings but I need, need, need a production ready persistence layer. Backbone has me spoiled in that area.
Ember data has a bigger goal than this and, yes, it takes time to get it right.
The "run loop" hooks into the existing browser's event loop in order to coalesce side-effects. This is exactly the same thing that the browser does when you make a number of changes to the DOM in an event handler.
There is nothing strange going on here.
As for the even driven stuff. Not sure what you mean by that, the run loop is not to dispatch dom events but to settle the bindings asynchronously (with the benefits of not triggering multiple changes for the same property within the same run loop and having a comprehensive pipeline to get data on the screen).