Wow, that's amazing that you were able to get licensing to sell Disney and Hello Kitty...most independent makers can't even begin to afford that.
In answer to your question, I've done collaborations with different on campus groups before, primarily Band Boosters and FFA in my case. We agreed upon prices for the items they would order from me, then they set their own prices to offer to the public for the fundraiser, did all of their own advertising, took all of the orders within a specified period, and then brought me the final list of what they needed. I took a smaller profit than i normally would have gotten on the items but I also didn't have to do any of the heavy lifting in terms of promotion and orders/money collection etc.
With some of the school groups I've worked with, the administration had to give final approval (for example on the items that used the school mascot they wanted to make sure it was an accurate and appropriate depiction), but in other cases the admin let the organization pretty much have free reign on items they wanted to sell. Also in some cases the money had to pass through the activities office and have proper paperwork in place (formal PO's, Requisitions, W-9 on file etc) and in others, they handled their own accounts and basically just cut me a check.
What it boils down to is that each district sets their own policies so you need to make sure you know what they expect.
