If your model has no identifier, EMF Compare tries to match elements using metrics to compute the "similarity" between your elements. In this case, the two Building objects are too different to match, so EMF Compare doesn't see them as being "the same" and you get an add and delete differences.
You will have to either make sure your models use identifiers or customize the proximity engine for your needs if it doesn't work for you.
The results you're describing here don't really make sense. The "move" detected by EMF Compare should be "titi" and not "toto". The quantity change should be detected nonetheless unless you have changed he feature filter somehow? Could you provide us with the models you're using so that we could try and check what's happening here?