I have indeed read the book you referenced, at least as much as I could stomach. They're quite ill informed, and we can get into that but first on a couple of points you mentioned:
To start with Mars has practically endless water. That's rather evident on the poles, but we discovered back in 2013 that even the 'desert-like' images you associate with Mars, the surface regolith is surprisingly moist at somewhere between 1.5-5% water by weight. So a typical analog given there is that if you heated about a cubic foot of soil, you'd be able to evaporate out upwards of 2 pints (or 1 liter) of water. So the whole plot in "The Martian" about these esoteric things he had to do to just get water was just based on ignorance, which was the state of knowledge prior to 2013. Of course humans on the surface would have discovered this in a matter of minutes, but we're relying on probes and rovers - so instead it took us half a century.
Similarly, radiation on the surface of Mars is somewhat less than what astronauts are the ISS are exposed to. The huge numbers you're referencing are probably either from stuff like that book you mentioned, which is wrong about most of everything it claims and/or equivalently being quite misleading by e.g. referencing exposure levels during flight from a direct solar flare, which would indeed be quite toasty - but is something that can be easily worked around. Water itself, which we'll need to bring plenty of, works as an excellent radiation shield.
Near to every argument made in your referenced book, at least to the point that I was able to read, is mostly uninformed and/or disingenuous, but this already getting quite a bit longer than I intended. If you're into reading things that don't just confirm your biases then I might recommend this [1] book instead. And it's written by an aerospace engineer with an extensive background of research into the topic, instead of a comic book artist. That's not an appeal to authority, as there are plenty of people with no background in space who are extremely well informed. But it's also true that those who are misinformed, universally, have no relevant background in space.
[1] - https://en.wikipedia.org/wiki/The_Case_for_Mars
To start with Mars has practically endless water. That's rather evident on the poles, but we discovered back in 2013 that even the 'desert-like' images you associate with Mars, the surface regolith is surprisingly moist at somewhere between 1.5-5% water by weight. So a typical analog given there is that if you heated about a cubic foot of soil, you'd be able to evaporate out upwards of 2 pints (or 1 liter) of water. So the whole plot in "The Martian" about these esoteric things he had to do to just get water was just based on ignorance, which was the state of knowledge prior to 2013. Of course humans on the surface would have discovered this in a matter of minutes, but we're relying on probes and rovers - so instead it took us half a century.
Similarly, radiation on the surface of Mars is somewhat less than what astronauts are the ISS are exposed to. The huge numbers you're referencing are probably either from stuff like that book you mentioned, which is wrong about most of everything it claims and/or equivalently being quite misleading by e.g. referencing exposure levels during flight from a direct solar flare, which would indeed be quite toasty - but is something that can be easily worked around. Water itself, which we'll need to bring plenty of, works as an excellent radiation shield.
Near to every argument made in your referenced book, at least to the point that I was able to read, is mostly uninformed and/or disingenuous, but this already getting quite a bit longer than I intended. If you're into reading things that don't just confirm your biases then I might recommend this [1] book instead. And it's written by an aerospace engineer with an extensive background of research into the topic, instead of a comic book artist. That's not an appeal to authority, as there are plenty of people with no background in space who are extremely well informed. But it's also true that those who are misinformed, universally, have no relevant background in space.
[1] - https://en.wikipedia.org/wiki/The_Case_for_Mars