You're obviously still conflicted. As others have suggested, I wouldn't rush to do anything. Give yourself a month and see how you're feeling.
H right now is intoxicated with OW, he has blinders on and isn't seeing reality. There is actually a chemical reaction in the brain that clouds our thinking and blocks critical judgement when we are feeling "in love" or infatuated. It's an evolutionary mechanism to get us to drop our guard and let people in for the purpose of continuing the species.
Therefore, he is not "himself" right now, far from it. This is temporary, it lasts from weeks to months and then it wears off. For affairs, it seems to go 4-6 months before people emerge from the haze. What that means is that you may not get introspection or any type of "what am I doing?" type thoughts on H's part during this period. Instead, you're likely to find him convincing himself that what he's doing is right, that he is righteous, and that all this is somehow your fault because of prior actions either real or imagined -- and he's looking to reinforce that belief based on what you do now. He's dying to manipulate you into doing and saying things that will reinforce that he's making the right choice.
When you GAL, 180, act-as-if you derail their expectations, don't play into their script, and the resulting confusion can accelerate their moment of clarity and critical thinking. That's not to say they'll just decide to come back when that point arrives, but that's the point where you can *start* to make progress. Until that point, all you can do is tread water.
What I can tell you is that your H is still in there somewhere, and you *can* forgive him for what he's done and trust him again if you choose to. The path to getting there is long and painful, and requires a huge commitment on your part. It may not be worth it to you when you do your deep soul-searching, but maybe it is -- only you know that.
In terms of the property separation, whatever you do can be undone later, so I wouldn't worry to much about any of it being final. Same thing with divorce really, you can always get remarried, so these milestones aren't really meaningful in themselves, they only carry the meaning that you attach to them.
Unfortunately, stonewalling can play into the WAS script that you are the bad person. If you block their plans, you're not giving them the space they want. Generally you don't want to help them, you want them to make all the plans, set all the appointments, etc., but if they do that, I wouldn't play games like not showing up. You should definitely have your own lawyer and make sure what you're entitled to and that you are protected. At that point, however, I don't believe you're helping yourself or the situatoin by intentionally derailing H's train.
What's the situation on the house? Is there a mortgage? If H surrenders the deed to you he is also handing over the mortgage. You might want to push for some level of financial support at the same time so that the payments aren't a huge burdon.
Accuray
Married 18, Together 20, Now Divorced M: 48, W: 50, D: 18, S: 16, D: 12 Bomb Dropped (EA, D): 7/13/11 Start Reconcile: 8/15/11 Bomb Dropped (EA, D): 5/1/2014 (Divorced) In a New Relationship: 3/2015