My fears of others anger is that I am being held responsible for somebody else's issues, and I feel the threat of abuse as a 'punishment'.
This is huge. This is where the fear based response comes from I think and therefore the reactionary defenses that we put up that leave others scratching their heads as we shut everything down with yelling or walking away without explanation. Healing this promotes trust that even if you 'agree to disagree' that you both care enough to at least try to understand each other. That leads to the 'misunderstood' issue that so many of us carry - which is usually a huge part of the miscommunication issues that lead to anger. One thing links to another to another to another.
This is where the 'Complex' part of PTSD rears its head. The PTSD issues are like trying to remove a vine from the walls of your house. It wraps around itself. You think you have a grip a huge piece but it is stubbornly wrapped around another piece then bam!!!! Something you thought you had dealt with comes back again. It feels like you have gotten nowhere but taking the time to look at the pile of the vines you have removed rather than focussing on what is left on the house allows you to see what you have accomplished, not what you have left to do.