I'm also curious as to the answers you might give in response to Harry's questions.

As distinct from "Beliefs" in a conventional sense, these are clearly a core set of foundational "Business Partnership Principles", adhering to which is quite possibly the most fundamental reason for the partnership having been successful and surviving for as long as it has.

From what Fred Wilson has posted in his AVC blog about his partnership in USV and their business focus and methods preferences, it would appear most likely that that partnership's longevity and success also arises because, as Fred has further indicated here, USV also adheres conceptually to these principles albeit in form modified to their particular business focus.

Constructing viable and lasting partnerships - especially where large sums of money are involved in potentially high-risk venturing activities - is typically one of the most challenging things to do because everyone brings to the party their own personality, "beliefs", expectations and ego: A scenario often worse than even any dating situation might deliver and there are no pre-nupes!

As Harry Demott observes, what you have laid out here Brad is "Clean, concise and clear": I would also add "unequivocal"; exactly the basis upon which to build any partnership for lasting success which is the specific point I'm establishing here ~ "beliefs" are malleable, amorphous whereas core principles are explicit and definitive.