identify vulnerabilities in the seven domains of IT within the organization.

just list possible roles that may exist for this scenario. You can just make up the name of the role but please explain what the role does.
identify threats to the seven domains of IT within the organization. This is not necessarily based solely on the scenario because threats are not listed; just list threats that may exist, in general, to the seven domains in the context of how they may exist in this example. For example, for the workstation domain, this scenario indicates that Windows 7 workstations are in place.
identify vulnerabilities in the seven domains of IT within the organization. This is similar to #2. This is not necessarily based solely on the scenario because specific vulnerabilities are not listed; just list vulnerabilities that may exist, in general, to the seven domains in the context of how they may exist in this example.
identify threat/vulnerability pairs to determine threat actions that could pose risks to the organization. Your assigned reading should assist with this question.
estimate the likelihood of each threat action. Your assigned reading should assist with this question (just the likelihood not impact).