You have nothing to fear but fear itself. Letting go doesn't mean that you are giving up. It means that you are detaching and moving forward w/your life and allowing God, time and space to work on your h. Letting go is also giving yourself the gift of time and space and to rediscover the person that you once were and to do the things that you've not been able to do for many years.
We all have had the fear of disconnection, but in his world, time is very, very slow and he is expecting you to be right where he left you. He's not able to recognize that time doesn't stand still and things can change on a dime. You can only control you, your emotions and what you do for yourself. You have no control over him, what he does or thinks. Unfortunately, you have to learn to be patient and trust in DBing. I do want to point out that DBing is not just to help you reconcile, but it is to help you in your every day dealings w/people and it teaches you how to react and/or not react to behaviors, actions of statements of others.
The only two that I feel that are truly safe to discuss at this time are numbers 3 and 4. As we often point out, discussions about relationships, affairs, do not go over well w/the wayward spouses. I do not think your h is at the point of having a civil conversation about it.
As for the silent treatment, many of them do this. It is a passive way of "punishing us" for whatever reason. The best thing to do is ignore the behavior. I know it gripes you to no end and do not apologize again for whatever happened previously. You've already done it once and that is enough. When children misbehave and are on the flooring screaming bloody murder, the best way to get them to cease the behavior is to ignore them. The silent treatment could very well be a way to annoy you so that you start a conversation about it and then it escalates to a heated discussion. For now, I would most certainly leave no. 1 on the stove to cook a bit longer.
Also, I want to point out that lying is one of the sins of the crisis person. If their lips are moving, they lie and sometimes they lie so much that they begin to believe their own lies. Take what he says w/a grain of salt.
If you don't want him to move out, they don't give him the idea to do so. Maybe he's hoping that you'll tell him to leave to make it look like you are the bad guy here. If he must leave, let him do it on his own, if you can stand it for a while longer.
My xh left came back, lived at home 7 months and he continued to threaten throughout the 7 months of leaving. So one day, I had enough and came home from work and told him that it was time for him to leave. He sat on the couch and cried like a baby, but I had had enough and didn't change my mind. He finally got himself together and left a week or so later and never returned. The walking on eggshells was stressful. The mood swings, the lying, being sneaky, gaslighting and the threats finally did me in. After he left, my home became more peaceful and my cat stopped losing his hair from all of the tension and stress in the home.
You will need to dig for more patience. I know it's difficult to ignore them when they are under the same roof, but you will need to find a way to view him as a visitor from another country who has no ties to you.
If you keep you conversation on "safe" subjects, you will be okay. The one thing that concerns me is that the conversations may start out okay, but then they go downhill because he starts baiting you and then come back at him. Change this dynamic. When he baits you, continue your conversation as if you didn't hear him doing it or better yet, state "h, when you are calmer and ready to continue the conversation, I will be happy to do so" and then end the conversation w/goodbye or have a nice evening and hang up the phone. I have found that when they start that baiting stuff, that changing the subject completely will stop them in their tracks because it throws them for a loop.
You will know when you've had enough...but it's not today.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.