NHK - I just found something interesting which may mean more research...The FAA rules that you cited are for Part 107, which, for the most part, cover Commercial pilots not falling under Community Based Organization Guidelines (like those of the AMA) and section 336.
Model Aircraft
• Part 107 does not apply to model aircraft that satisfy all of the criteria specified in section 336 of Public Law 112-95.
• The rule codifies the FAA’s enforcement authority in part 101 by prohibiting model aircraft operators from endangering the safety of the NAS.
As there have been recent changes to Part 336 in the past few months, and they are not covered in these rules from 2016, I wonder if there's a different set of rules that are more strict for hobbyists. It could potentially be interpreted (as I have not read all of Section 336 or its changes) that the 100 mph limit is not enforceable on a hobbyist level aircraft, because they are to follow the guidelines of the community based organization, which, in theory, should be as strict as, if not more so, than the Part 107 rules.
Also, I can see people interpreting and arguing Part 107 to allow them to fly really high. For example:
• Maximum altitude of 400 feet above ground level (AGL) or, if higher than 400 feet AGL, remain within 400 feet of a structure.
So, if I were flying within 400' of the Empire State Building, I could fly all the way to the top of it, which is 1,250 feet high...if we ignore that it's within restricted airspace, as I believe most of New York City is now that President Trump and his family have restrictions around their homes at Trump Tower (unless those were just Temporary Flight Restrictions; this is where there's so much of a mess and it's just easier for me to say, "You probably shouldn't try flying a drone in New York City unless you're indoors.")