The main thing to remember when trying to determine a ruling that is not explicitly addressed is that if your idea makes sense, then it is probably right. However, when making rulings based on the rules and the cards, is that if it isn't there, then it isn't there. If a card says a site counts as a Haven for purposes of healing, that does not mean the site counts as a Haven for any other purposes. If a card says it can be played as a resource, that does not mean it counts as a resource at any time except when it is being played. Remember: If it isn't there, it isn't there.
The Council of Elrond is attempting to rationalize and merge all the rules, CRF and errata into one easy to use and read rulebook. We will place it here when it is done.
If you have any further questions concerning MECCG, join the online MECCG community and email your the message.