Large portions of your question are off-topic for Server Fault - [questions about licensing are explicitly specified as off-topic](http://serverfault.com/help/on-topic) because they involve complex legal issues that are organization-specific, and need to be worked out with the software vendor.

Points 2 and 4 of your question fall afoul of this rule: These are questions you *must* ask your Microsoft licensing representative (or if your organization does not have one, contact Microsoft support and they'll put you in touch with someone).  

This sort of question falls into the category of "If we give you bad advice nothing happens to us, but Microsoft may sic their lawyers on you, and your company may not survive", which is why we don't answer them (and why I have marked your question as a duplicate of the [Canonical Licensing Question](http://serverfault.com/questions/215405/can-you-help-me-with-my-software-licensing-issue)).

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Points 1 and 3 of your question should also be addressed to Microsoft since their procedure for handling downgrades is closely coupled with licensing, but as they've been stable for the last 2-3 years the answers Longneck and Travis provided cover the technical aspects pretty thoroughly (I specifically waited for at least one of those to pop up before closing the question because this may be useful to others as well).  

Both answers seem complete and correct to me (though they're phrasing things slightly differently) - Any gaps or errors in those answers can be filled in/corrected by the Microsoft representative who will walk you through the downgrade (and who you'll have to talk to anyway - Microsoft goes out of their way to make this difficult because they *don't want you downgrading*).

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Short version: Your question wasn't closed because it's bad, or because we don't like you - it was closed because *we **really** don't want to screw you over by giving you bad advice*.