I believe that you are basing this on the fact that Lois was interviewed for several hours. I've done some thinking on this. I think that the FBI brought in some new investigators who had very little in the way of prior knowledge of the case. Their job was to ignore any and all previous assumptions and to start fresh. The reason behind this was to make sure that nothing was overlooked in the initial investigation. This is a very good practice in a case like this because of its complexities. Given the above it would only make sense that they would have spent an extra amount of time with Lois to clear up the types of things that you mentioned above. After all it is the family that most often is behind these things. Now to burst your bubble.
We have no idea if these new investigators found anything or not. It leads to the same kinds of wild speculations that went on early in the case. For all we know though, the new investigators my end up drawing the same conclusions that were previously reached. Until we get some more information out of LE we can only GUESS as to what they may have uncovered. It is very possible that nothing new has been found.
Theory?
Sorry sandude, but that's just plain silly. The FBI were in on it immediately as they are all alleged kidnappings. And, no, I was not basing my remarks on a long interview of Lois.
I suspect, though, that when they (LE/FBI)nail down the status of their marriage, the investigation might take on a new tack.