re: CAT-1
That looks familiar; probably one of the references I saw about situations overwhelming the local authorities.
I think FEMA comes to mind first because it's been around so long and everybody knows the name. The idea that DHS is about more than terrorists is probably not clear to a lot of people...and possibly to DHS itself. Have you noticed how often terrorism is referenced as the first example of an incident? DHS may be so focused on terrorism that it's lost perspective about its overall mission.
If you're studying the document in depth, you're a better man than I am, Gunga Din. I skimmed looking for the pertinent sections.