To my US friends :
What I hear here only confirms my earlier thoughts about FAA and ICAO differences based on the old " "we do things differently in the US because we have most of the aircraft flying in the world" That was true until 20 years ago, now Asia is catching up , and you get more and more non-US airlines coming into your airspace. Have to get used to it , the Chinese also are going to outnumber you in number of aircraft in a few decades.
Even with Trump around, it is just plain demographic arithmetic.( and Boeing/Airbus order books)
You need common rules to fly together and I bet you FAA rules it won't be.
Time for the US to learn and apply ICAO phraseology I would say .An better make a plan do this smoothly now instead of in a hurry after 400 bodies on the ground somewhere.
On the 250 Kts below 10.000 , this is not to bother pilots nor a " power" thing for ATC . It is there for 2 things :1) giving time to spot and avoid VFRs (and give a chance to VFR to spot you) and 2) survive a hit from a bird in the windscreen ( Civil aircraft certification limit) This is a rule, written down in AIPs. So individual controllers have to apply and you have to follow , or make a request to differ.
And the outcome of that request will depend on what the local authority (e.g. FAA) wrote in the ATC Ops manual that controllers have to follow.
ATC is not there to " make " or " wave " rules . it is there to apply them for the safety of everyone around , not only one aircraft. . As to the machos " My Ship" I do what I want , I pay you ..etc.." yes..good old discussions for the bar in front of 2 beers. Reality is very different . You know that.