The Most Effective and Efficient Approach/outlook to manage and mitigate risks is the Pessimistic one ! Do you Agree ?

I think the realistic approach is the best. When you are doing your risk analysis, include everything that could possibly happen, and then you assign it a value based on its impact, and its possibility of occurring. Don't ignore anything that is mentioned.

I think that having a slightly pessimistic outlook when identifying risks is good. I've worked for optimistic companies that seemed to get caught by surprise by risks/issues that should have been easily identified well in advance.

In agreement with Aaron, from my point of view the identification/ revaluation of risks should be done with a critical attitude, as you are trying to find problems prior they emerge as a risk to the project, I think it is appropriate the attitude that "anything that can go wrong will go wrong". The critical attitude should be applied to the specific project context with focus on assumptions, activities and decisions that might endanger project success prior, during and after projext execution. In the critical attitude involve all relevant stakeholders with their different perspectives. In a nutshell, critical examination must be done.

Continuous risk identification is a responsibility of the whole team and must be on the weekly teams meeting agenda. There is no reason for mental panic at all. Of course, team members need to understand risk management process, roles and responsibilities being applied to the project.