Re: 737-800 v Max-8
"The different distances between point of thrust, direction of thrust & CoG has introduced enough of an issue that the aircraft need an automatic trimming system [MCAS] to deal with the problems it can cause"
YES! (though maybe centre of lift comes into the arithmetic somewhere too, I forget).
This is *the* crucial factor in this whole sad MCAS story. The 737 MAX wasn't going to be airworthy without overriding the 737-vanilla pilot's inputs occasionally, because the MAX's weight and geometry (and thus its flight characteristics) were noticeably different than its vanilla predecessors.
The rest of this sad MCAS story follows from that previously-hidden change, and whether or not the MCAS is found to be involved in this latest incident, Boeing and the FAA clearly already have some important questions to answer.