Hi Tony,
As you well know, I am in no position to "do the math" with this question. This is why, several years ago, I went on a mission to talk to as many degreed physicists as possible about this very question. They all had Masters or PhD's, and most were teaching in local colleges. None worked for NIST or the government (except as employees of public universities etc). The idea was to get away from 9/11 Truth advocates like you and "debunkers" like the people here. I asked almost 100 physicists, almost all of whom refused to talk to me about this because they considered the whole debate to be beneath them. 14 were willing to talk with me and answer my questions. The questions I posed: "When the Twin Towers began to collapse, is there enough energy for the collapse of one floor to initiate progressive collapse of all floors? And approximately how much dynamic energy is released by the collapse of a single floor?" Without hesitation, every physicist said absolutely yes there was enough dynamic energy generated by gravity to initiate progressive collapse.
The second question was a little tougher. The amount of dynamic energy depends on how high the floors are, the materials, the amount of flexibility in the columns and beams, etc. But in general, the rough-guess answers were that the dynamic energy of collapse was about 30x the static energy of the building just standing there. Considering that the building was designed to handle 3 to 5 times the static load, every physicist told me that there was such an enormous margin of error that none of the variables would make any real difference in the inevitability of the collapse.
This isn't all the numbers you are talking about, of course, but since doing this very long and rather scary exercise (I'm a little thin-skinned about rejection ya know) I have been pretty firmly convinced that real experts are pretty much unanimous about this question.