Your communication idea, the circle of trust, is interesting. I like your awareness of writing things down and prioritizing which to start with.
I totally understand your list you have so far, the things you need to know. I would like to extend to you a different view. In time those things that you need to know right now, become a lot less important. You really do not need to know those answers. Honest.
I see a lot of expectations of how you think this should go and should have to go. Expectations are a dangerous mix this early into this situation. You may well expect an answer, but H many not even know, at the moment, why he did what he did. Emotions are irrational, and it takes time to uncover the reasons/events that underpin them.
For what it’s worth, your first priorities should be to let him talk. Let him discuss him. This whole situation is basically about him, not you. All his behaviours are due to whatever is going on within him. So, let him talk. Follow whatever lead he is willing to do. You need not forgo your questions; be patient they will keep. And you might just find they are not nearly as important as you feel they are.
You have a rare opportunity, a spouse who wishes to talk. Take it slow. H is like a timid squirrel, and will run if bombarded with too much. Don’t worry the truth will come out - in time.
So a question, can you be strong enough and patient enough to allow him to walk his path at his pace? I think you can.
Best wishes.
DnJ
Feelings are fleeting. Be better, not bitter. Love the person, forgive the sin.