ISO 27001 risk methodology and corporate guidelines according to ISO 31000
Whether you will change your information security Risk assessment methodology or not, this depends on what you will write in your enterprise risk management (ERM) documents (per ISO 31000). So if your corporate ERM documents allow greater freedom for risk management in particular areas, then you probably won't have to change your ISO 27001 risk methodology, and vice versa.
Therefore, if you resolve this situation with strict agreement with this business unit, you will still be compliant with ISO 27001.
ISO 27001 Risk Management
The problem is: is it necessary to be a clear link between a particular risk and a particular Annex A control? I mean; each Annex A control (if we choose to implement it) can be tracked down to a particular risk? And if its the case, then what kind of risks lead us to controls such as A.5.1.1, A.5.1.2?
Answer:
Yes, it is necessary to link particular risks with controls from Annex A because you have to show this relationship in the Statement of Applicability (clause 6.1.3 d) - you have to provide justification for inclusions of particular controls.
Regarding A.5.1.1 (Policies for information security) - basically you can select this control for any risk that is related to organizational issues; A.5.1.2 (Review of the policies for information security) - you can select this control whenever you have a risk related to documentation that is not updated.
Difference Between ISO 22301 & ISO 22316
ISO 22316 is not published yet - currently it's status is "Under development" - see official ISO website here: https://www.iso.org/standard/50053.html
It is difficult to say what the standard will contain before it reaches the "DIS" status (the official draft).
Recertification or surveillance audit?
1. We have moved into a new location and
2. We have a new name as well.
We were due for surveillance audit in March'2015. Should we get re-certified or Surveillance Audit is good enough for us?
Answer:
If your main business remained the same, I think you can go with your surveillance audit as planned, and go for the re-certification only once your certificate expires.
However, you should consult with your certification body before the surveillance audit begins.
I have downloaded a copy of your book 9 steps to cyber security - Excellent reading.
Answer:
This is correct, cyber security is not explicitly mentioned in ISO 27001 nor ISO 27002. And you are correct, the IT controls you mentioned should be used to protect your information systems from cyber threats. However, as I mentioned in my book 9 Steps to Cybersecurity, IT security is not going to be enough - other organizational controls, as well as human resources management controls (e.g., training & awareness) are also needed.