Re the satellite heat spike.
All I can find is a report on NBC that indicates it was a mid air explosion, not on the ground. Also says that the same satellite would be able to detect the heat signature from a missile which it did not. But I don't think anybody is still pointing to that as a possible cause anyway.
Even if it was a mid air explosion, it clearly does not get us any closer as to what caused it (bomb or fuel tank) or if the explosion was the primary cause or a result of a structural or control surface failure that then caused a structural failure of some kind that consequently ruptured and ignited the fuel tanks
All it does is confirm what many have already alluded to and that is there was a major fire (explosion) mid air and what the autopsies seem to confirm with fire being a major cause of death (as posted above).