I haven't read most of the report, but the front matter and chapters indicate a good review of the hazards to me. It also indicates the extreme conservatism with regards to risk that NASA is taking. The number of relatively low risk hazards assigned barrier status would have been laughable to earlier explorers.

I think all of the risks in the report should be addressed to some degree, but reducing every risk to zero is a prescription for inaction. Inaction always runs the risk of missed opportunity and loss of control which the risk averse always seem to ignore. They always worry about the risk of doing something rather than the risk of not doing it. All good risk analysis must look at the issues from both angles.

Regards,
Mark