Will they check the stability of the airframe design? I ask because I read that the software was created to compensate for using dangerous forward weight placement to accommodate oversized engines without undertaking the expense of designing a new airframe. If that were true, it would indicate to me that Boeing knew in advance that they were selling a dangerous aircraft. I can't imagine that software tweaks would suffice to make it fit for human flight in that case.

The airframe according to reports has some stability issues at the edge of its flight envelope. That could have been resolved by requiring additional simulator training for pilots -- but Boeing chose the MCAS system to avoid the cost, and the revenue hit (reportedly $1million / plane by Southwest alone).