This is a great article. It is not “if” but “when you have a PR nightmare.
Your first point which is all about actions to take is critical. I recently wrote an article http://bit.ly/2tSNHZP about doing a “PR earthquake drill” i.e. practice before the adrenaline kicks in and your backs are up against the wall.
To that end we have developed the PR Response process map to help people start thinking about how they would respond, which we developed in our free Elements.cloud app. Very happy to invite you to copy the map in Elements: ping me an email email@example.com