Hadrt and Negri are simply put wrong, they are not used at all anymore for good reason. The cards they wrote were great, but the international system doesn't operate under the rubric that Empire outlined (IE the United Nations has become largely irrelvant, and it's disagreement isn't occuring). Along with tense relationships between russia, china and the United States where it is clearly not a co-operative international relationship in regards to security or anything really, yes it is safe to say you can ignore Hardt and Negri.
The multitude could of been sweet but that larger is becoming unworkable, I think there is potential for a Terrorism good argument with multitude thought along with other stuff about terrorism.
And he is describing the complexity K that georgetown read vs. NW at the NDT finals. It is important to note that was more a testament to Georgetowns preparation than the quality of that as an argument. I'd argue Georgetown won that debate because they had insane quality of intel on how Northwestern answers the critique and went with one that is a outlier of that set of responses ( Not liberal, has a better claim to this is how IR really is, is a epistemology argument as well for there advs). Burke is less of a security author than Mitchell, Burke makes a wider argument with security components.
I would not recommended Foucault as a security K. It is a lot harder to win a biopolitics explanation internal link to violence that will occur, instead Foucault's strength lays in A. being a sick epistemology argument ( I think this will be harder for you to pull off, it requires a much more exetensive knowledge of the background of the author as well as the politics of the area the affirmative is talking about) B. Different role of the ballot (This is the future of the critique and has impacted college critiques in a big way in the last year or two. Foucault has one of the few we should stop imagining ourselves as activist and start thinking of ourselves as intellectuals thinking about history rather than acting, this requires that you have access to a coach/camp lecturer to work through how to make these arguments. that's fine but it sounds like since you are asking this very broad question of what K should I read you don't have access to either.)