as well as the addition. Does it have permit for the addition?
Evidently the addition was not tied properly to the beams of the original house, but just sits on the bricks which are not meant to carry the weight. As far as this has not problem with the city, the cracks can be patched and should be stable after these years.
The leak to the panels on the underside is due to the low pitched roof (almost flat) that needs regular patching . The overhung tree branches make things worse.