2. How did Boeing get hold of this? Probably by sifting through archives after a criminal investigation was started. This is appears to be far less damning than a formal complaint to superiors.
Depends on whether there was pressure from above to just get it through certification, or a culture of cutting corners.
Reuters are reporting today that the FAA are super-unimpressed that Boeing knew about these texts etc some months ago but failed to disclose them. Makes a mockery of Boeing's intention to fully cooperate with the investigation.
Finally on an unrelated point, it's intriguing to see how certain sections of the aviation press continue to report this story - they're obviously keen not to upset one of their major advertisers. Thankfully no such issues in the mainstream press.