This sounds like the right approach, although I'd add some flexibility that makes everything in between possible. Ie, if you peer at one NAP, then you get some percentage of the peers routes. If you are at all NAPS, then you get 100%.
I think this is going to be very bilateral and that the details will vary all over the place. And there are some problems with the model, in that CIDR blocks are not internally local to a single area. In order for someone who holds a /13 to send just the routes local to the NAP you're peering at, they have to send you bits and pieces of their /13. This is "hard." I'm not offering this world model without caveats -- doing the right thing is going to take a lot of effort. But I think it's the right direction *anyway*. If I want to send my wife mail and she works at a company 10 miles away, it is *not* going to sit well with me that she can't get it due to a private peering or even public peering point that's dropping packets 2,500 miles from us. (We live with that situation today, and none of us likes it.) I also don't think it is "wise" (there's that word again) to eat wide area line costs with traffic that could stay local. I could go on and on about this, but I see that I already have.