The captain's home simulator is interesting. He could have practised all the scenarios large numbers of times. The plane handling, the systems management, the use of airspace, the approach and landing at some obscure destination etc.
As a captain, if he didn't know how to do that already then it would be a scary ride alongside him.
We may never know what happened on board this plane. If somebody can switch off the ACARS and Transponder then they may have the ability to switch off the CVR and FDR.
The Indian Ocean is a pretty big dumping ground and would need some sort off debris to identify a place to start searching.
I still reckon we are not being told the whole picture of what the authorities know, but if keeping quiet, means the possibility of getting back "hostages" then they have to do it.