Here is my idea for you convention logo: a clean and professional, all-encompassing emblem consisting of only your main PMS color, black and white. It would recreate great at any size, including embroidery. Being round also gives it the versatility to be placed almost anywhere and still function as an effective piece of design. I kept the NAMIC logo within its own area, as I am sure you have specific branding requirements as to how close other things can be to your brand without violating your predetermined guidelines.
I look forward to hearing what you think, and I will be around all night should you want to see any revisions or other ideas. Thanks!