Malaysia would be looking for the black box and concrete proof that a suicide attack was underway before admitting to any shootdown - even if it takes months. If the story somehow comes out before they have proof the shootdown was necessary, the second-guessing is going to be overwhelming.
Correct. In all regards.
The idea that the government of Malaysia would shoot down a commercial airliner full of civilians (2/3 Chinese nationals), and decide not to tell the public for days or weeks or months is just not credible.
They can not just say "well, we decided not to tell you for a while." The outrage would be massive.
How does the black box pinger work? Who receives the ping?