Hopefully the FAA won't just look at the software fix in isolation. Other questions about whether the aircraft is fit to fly include
1) Can pilots correct an out of trim situation at high speed
2) How did the missing AOA disagree light get through testing; are there other weaknesses
3) Boeing certified MCAS based on 0.3 travel but it could do 2.5 units. How did this occur, and have other self-certified items also changed since the paperwork was submitted
4) Why was MCAS code not written to level 1 spec. What else controls flight surfaces and is not Level 1?
5) Given two pilots did not recognise MCAS/trim issues, one crew after being told about MCAS, what human factors are involved in alerts/nnc's etc
6) Has the new bus interconnect for the flight computers being tested?
Really the failure of the design and engineering in MCAS is more like the canary in the mine...
G