So, maybe I can help clear up some confusion here, with the disclaimer that I Am Not A Lawyer, and any advice I give here is taken at your own risk; consult your own attorney. I have here in front of me the ASA's FAR/AIM 2017 Edition, which includes the newly-minted Part 107. I also have a printed copy of the AMA's rules and bylaws, to include the Academy of Model Aeronautics National Model Aircraft Safety Code, which you agree to follow upon becoming a member. All of that is available here:
http://www.modelaircraft.org/files/memanual.pdf
First, let's review again the 14 CFR Part 101, Subpart E:
(b) The aircraft is operated in accordance with a community-based set of safety guidelines and within the programming of a nationwide community-based organization;
So, this part "operated in accordance with a community-based set of safety guidelines" does NOT mean that you can only fly at an AMA sanctioned event, and doesn't require that you even be a member of the AMA... only that you follow their guidelines when you, say, fly in your backyard.
When they say "programming of a nationwide community-based organization" this is probably where the confusion comes in.
To quote from [Docket No. FAA-2014-0396] Interpretation of the Special Rule for Model Aircraft, available here:
https://www.faa.gov/uas/media/model_aircraft_spec_rule.pdf
The FAA is issuing this interpretation because we have received many inquiries regarding the scope of the special rule for model aircraft in section 336 of the FAA Modernization and Reform Act of 2012 and the FAA’s enforcement authority over model aircraft as affirmed by the statute. ...
...See Advisory Circular 91-57, Model Aircraft Operating Standards (June 9, 1981)...
...Section 336(a)(2) requires model aircraft to be operated within a community-based set of safety guidelines and within the programming of a nationwide community-based organization. Congress explained that it intended “nationwide community-based organization” to mean, in part, a “membership based association that represents the aeromodeling community within the Unites States; [and] provides its members a comprehensive set of safety guidelines that underscores safe aeromodeling operations within the National Airspace System and the protection and safety of the general public on the ground . . . .” U.S. House, FAA Modernization and Reform Act of 2012, Conference Report (to Accompany H.R. 658), 112 H. Rpt. 381 (Feb. 1, 2012) (discussion of special rule for model aircraft). Based on this language, which provides context to Congress’ use of the term “nationwide community-based organization,” the FAA expects that model aircraft operations conducted under section 336(a) will be operated according to those guidelines...
Ok so the FAA says you can fly Part 101 if you adhere to AMA's or some other organization's guidelines. Nowhere do they say you have to be a member. Let's look at AMA's rules, to see if you can
only fly at AMA sanctioned events if you DO follow their "rules":
1. Model aircraft will not be flown:
(a) In a careless or reckless manner.
(b) At a location where model aircraft activities are prohibited.
Nope, you just have to follow their rules (which generally mirror Part 107). If an LEO or an FAA inspector shows up, however, it'd be good to have an AMA card, a logbook, and a ops manual to smooth things over. Let alone a Part 107 cert.
Cheers