And finally, you can use our templates. We have specifically documents for the development of the Business Continuity Plan, and you can download a free version if you click on the Free Demo tab: https://advisera.com/27001academy/iso22301-documentation-toolkit/
Both concepts are related with the same thing: risks. Let me explain the relation:
What is the SOA? Is a document that includes the applicability of all controls (basically each control can apply or not)
What is the risk treatment? Basically is a plan that include actions to reduce risks.
The actions that you need to include in the risk treatment, are related to the security controls, but What security controls? Only the controls that apply to the organization, and What controls can apply? Depends on the SOA. So, in other words, the Risk Treatment Plan is the "implementation plan" for the Statement of Applicability.
There are some domains of control that are not related to IT. Example: A.7 Human Resource Security and A.15 Supplier relationships. But A.12 is directly related with IT because has controls about backups, malware, monitoring, technical vulnerabilities, etc.
Remember that there are a list of documentes that you need to be compliant with ISO 27001, and one of this is related to the control A.12.1.1 Operating procedures for IT management. To see this list, please read this article (you also can see a list of Non-mandatory documents) List of mandatory documents required by ISO 27001 (2013 revision): https://advisera.com/27001academy/knowledgebase/list-of-mandatory-documents-required-by-iso-27001-2013-revision/
Context and interested parties
You can do it in the same document (recommended), although you also can do it in different documents. The standard does not establishes that both paragraphs have to be defined in the same document, only establishes that you have to define them. If you need more information about how to define the scope, please read this article How to define the ISMS scope: https://advisera.com/27001academy/knowledgebase/how-to-define-the-isms-scope/
Keep in mind that the control A.9.4.4 is for utility programs (any software that you need for your activity in the organization and you install it in the system operative), so the first step is to identify them in your organization. Next step: There are unnecessary utility programs? If yes, delete them. Next step: There are some utility program which can access any people? If yes, is necessary to establish a password. There are systems with password that access different people? If yes, it is necessary to establish different users (not unique user administrator or root for all ).
In your case, my recommendation is: segregate functions, create a new group and include on it users that do not need administrator access, it should be only for 1-2 people (administrator systems). If it is necessary that other users have administrator privilegies, you can create another group, but independent of the administrator group.
Scope of ISO 27001 for a software project
You can include in the scope of the certification the activities related to your software project, processes related to your software project, department that works on this project, or you can certify all activities related to the whole company. However, you cannot certify only the project itself - the point is that your organization is certified, not your product.
Basically this is not recommendable, because there can be a risk which the organization cannot control (who updates the software?, who buys the anti-virus?, who makes the backups?).
To mitigate such risks (for the equipment that are not included in your scope, i.e. not in your asset inventory), you should develop a policy for the use of personal equipment of the personnel, it is known usually as BYOD (Bring Your Own Device).
It is not true. The Opportunity of Improvement are recommendations of the auditor, and never will be a Non-Conformity. However an observation yes, this can become a Non-Conformity if the organization do not resolve it.
For the internal audit the situation is the same, but in this case is would be interesting that you include in your procedure of internal audit the definition of each finding (Non-Conformity Major, Non-Conformity Minor, Observation, Opportunity of Improvement).