Ok, maybe one thread with all questions not 3. It makes in confusing.
Ok simple, do mediation, done that by the sounds? Then you have 2 options
1. Wait 12 months from time of separation. Then get divorced, then wait 12 months. From there it is hard for either of you to make a claim on each other's assets. However, if there is a property with both names on the title, things will get messy. That makes option 2 almost inevitable.
2. Apply to court, force him to resolve these issues. BTW a stat dec or what ever, to declare he doesn't have an inheritance isn't gonna work. So make sure all assets and information are provided to the court. They can order it and enforce it.