PJ2...
Your question re "123.45" is interesting. Many of us have postulated that a lack of comms from AF447 to "fellow travellers through the ITCZ" that night is indicative of something. Quite what, we aren't sure of course.
What we can say -- as you have alluded to -- is that exchanges of some sort on 123.45, in that area at that time of day, are the rule rather than the exception. For there to have been no participation by AF447 is, to me at least, a possible hint that things weren't quite "normal ops" up front. I'm choosing my words carefully as I have no idea what the apparent failure to use that resource specifically means. There are so many possible reasons for it: one or more radios inop (we have an indication pre-takeoff of a possible problem in this area); something else on the flight deck taking priority (for a longer time than we may have been supposing); and on and on...
At this point this tragedy must be accepted as a puzzle with too many pieces missing to solve it. All we can hope is that the DFDR and the CVR, along with the aircraft remains of course, will provide the investigators enough pieces to solve this puzzle. I, for one, am optimistic.