I agree with statement 2 but not statement 1 and I would add a statement 3:
1/ If a role or a circle anywhere in the organization has a domain, the domain (and any accompanying policies, if any) applies (or apply) to all roles in all circles of the organization.
Part of it is false, if a role in a sub-circle has a domain but the circle itself doesn't have that domain (meaning it hasn't been delegated to the circle), then this role owns the domains only in regards to other roles within the circles, not outside the circle (just like policies in statement 2). You can't control what hasn't been delegated to you.
Statement 3 just for fun: If a circle has a domain that hasn't been delegated to a role within that sub-circle, then the Lead Link of that sub-circle can define policies to constraint/authorize how other roles/circles outside this sub-circle can impact that domain.
Hope I am right..