I guess I can repeat it one last time, with your interpretation of the code (by using motor in a manner consistent with instructions), R/C flight would be illegal using motors made for rockets and not R/C aircraft (which seems quite common these days). It's contradictory, and thus leaves a bit of a loophole in it's wording.
I know you haven't advocated suspending membership, but what I'm saying is if you're so concerned about people doing things that break NFPA code (not actually a law), then we should go after those bad people that do so, no? I don't see you posting in the other forums stating this.
The instructions mention storage and ignition. As you've said the code isn't that long or complicated, so it should be fairly clear.
@arelee if you want to please the nanny state and be totally in the clear, contact a local university and ask for some help from students. If your project is part of a universities activities then you can apparently ignore this entire thing.
1.1.4 This code shall not apply to the design, construction, production, manufacture, fabrication, maintenance, launch, flight, test, operation, use, or other activity that is connected with a rocket or rocket motor where carried out or engaged in by any of the following: (1) National, state, or local government (2) Individual, firm, partnership, joint venture, corporation, or other business entity engaged as a licensed business in the research, development, production, testing, maintenance, or supply of rockets, rocket motors, rocket propellant chemicals, or rocket components or parts (3) Colleges or universities