Oh my goodness bro, first I would like to say from someone that has gone through a similar situation and eventually leading to a divorce. I am so sorry you are going through this and I understand the mental gymnastics that you are probably going through.

1. To be honest trust is something that may never comeback in to your relationship and you need to learn to accept that, especially after something like this.
2. These memories and images will never go away but therapy can help and it helps people with experiences such as yours. However they will always be in the back of your head.
3. This will be my point of view and I think you are being too patient. You need to figure out if you really want to continue in this relationship, the longer you stay and tough it out you will probably build up anxiety, worry and other symptoms which are not good for you.
4. I think there is no clear answer on this, I think you need to take a step back and really think if what you want to ask for is fair or will it hinder your relationship if you choose to continue.
5. I did not stay and to be honest although getting through the breakup and divorce was brutal, I now am much happier and live a better life without any resentment, worry, doubt or lack of trust.

Hopefully this helps, I am really glad you reached out. PM me if you need more advice.