Yes I have read the references you cited. That's how I know the arguments against life on Mars are flawed. This doesn't mean the case in favor of life on Mars is proven, only that the frequent claim that life on Mars is "virtually impossible" is not supported by the evidence.
As an example, the NRC report you mention specifically mentions that arguments against life on Mars are based on the *presumed* lack of liquid water. When reading scientific reports you HAVE to keep in mind the qualifications and limitations such reports describe. You don't just ignore them. In this case, there is steadily increasing evidence that liquid water can exist on Mars at least for short periods. This is fundamentally important to arguments discussing the likelihood of life on Mars, which the NRC report writers fully knew. To them as scientists simply saying such arguments are dependent on assuming liquid water couldn't exist there was enough.
However, to those who only look at conclusions, you have the tendency to overlook the assumptions and qualifications a scientific report may describe. (This happened also with tragic consequences in the Columbia accident.)

In regards to Barry's book, you inadvertently give strong evidence for why you should read a book before you criticize it (most scholars would be amused that this position has to be justified): by taking the opinions of others who claim to have read Barry's book you incorrectly assume there is a chapter devoted to conspiracies by NASA. In the book there is a chapter discussing possible reasons why NASA has not conducted further research on the life on Mars issue. In this chapter, Barry offers *SEVERAL* different reaons why this might be the case. One suggestion he offers is that there is religious opposition to revealing that life on Mars exists. Then, in a single paragraph, he offers the possibility the military might want to use any such life as a weapon, and NASA is beholden to the military.
If I fault Barry on this chapter it's only because he rather implies NASA DOES believe there is life on Mars to begin with. I myself think a more likely reason it is not pursuing more research on the idea that Viking did find life on Mars is because of the natural conservatism of scientists, especially toward such a revolutionary concept of life on another planet.

Bob Clark