A lot of preparation went into this plan = We put a lot of preparation into = We devoted a lot of preparation to. "to put a lot into something" means to use a lot of effort when doing something. When she was to arrive = When she was (due) to arrive; when she expected to arrive. "to spirit someone in" is not something I have seen before, but it sounds familiar. I think it means include them "in spirit"? "in spirit" here means not physically, but with your intentions. I am not sure, someone else may know the meaning. If I saw the whole paragraph, i could probably tell you. Nor was she personally close to Obama, ( [such as] in the way James A. Baker III was [close] to President George H.W. Bush. )

I'll just explain your third question (Ian's covered the rest). When someone is "sprited away", it means they are taken away secretly (as if spirits came and took them away). You can understand "spirited in" with the same idea: he was brought in secretly by the Americans.

1- Like eggs, sugar and flour go into making a cake, also many immaterial things "go into" it with the ingredients. You can say that a lot of (determination, effort, love, sentiment, hope, creativity...) went into the making of something. 2- At that moment, the action of arriving did not happen yet, so you can't say "arrived". She was (due, expected, going) to arrive. 3- The verb "to spirit (away/off)" means to carry away in secrecy or in hast. I do not know the exact relation to the noun "spirit". 4- ... and she was not personally close to Obama in the way Baker was not personally close to President Bush. >>> ...(and+negation) x (she was personally close to Obama in the way Baker was personally close to President Bush.) >>> ... nor was she personally close to Obama in the way Baker was personally close to President Bush. >>> ... nor was she personally close to Obama in the way Baker was close to President Bush. I hope this helps!