The interpretational PMP question section of this article will help you with SPI: www.project-management-prepcast.com/pmp-exam-questions
There is a worked example. I'm not sure what you mean by 'critical path SPI' as something different from SPI. Perhaps someone else can shed some light on that. Did you mean CPI?
As for the question about holidays, in the real world, any one of those options would be OK. You'd make the decision based on what was best for the project and the team at the time. Where did this question come from? Without more context I can't tell you what the "right" answer is, but perhaps someone with a better memory of the contents of the PMBOK(R) Guide can point us to where that would be covered in the text.

There's a discussion here that might help you with the difference between smoothing and compromising: www.project-management-prepcast.com/kune...e-vs-smoothing#20342

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If the risk didn't happen, it can be closed in the logs. I wouldn't remove it as changing the status to closed gives us the historical information.
If the PM is on leave and something happens with a resource, the team should either know (because the PM has done a handover) or escalate to someone who does know, like the sponsor or a team leader.
There is no average conflict solution. It depends on the situation.

Does that help?