Ron, it's important to note that you're looking for a "one-off" approval for your aircraft, not an approval for all RV-14's. The MD-RA document is a summary, and you'll note that nothing mentions information from the kit manufacturer.
You do need to perform a mechanical evaluation, which means you'll need something to evaluate it to. If you're not capable of doing a full stress analysis of the airframe yourself, you'll have to get something from Van's that says that an RV-14 built according to plans is capable of sustaining the desired G-forces. You'll then need to certify that the basic structure of your plane was built according to plans... No deviations to the structure. If you've made changes to the structure, you'll need to document them and show that they haven't changed the stress paths in a way that would reduce your margins while doing aerobatics.
I seem to recall having a similar summary document from Transport Canada at one point... An Advisory document for their offices. I'll see if I can find it.