a) There are multiple foreign nations who have travelled to space - many of whom are openly hostile to the USA. None of them blabbed?
During the cold war the US expressed open skepticism against the Soviet Space Program, and vice-versa.
b) There are multiple non-government agencies (SpaceX, for example) who would have to have been in collusion. None of them blabbed?
NASA is actually composed entirely of non-governmental agencies called government contractors, public-private arms of the state which operate within the government's secure realms.
c) Not one "death bed" confession from an astronaut? Really? Not a single one?
Buzz Aldrin's entire personal and professional life revolves around the fact that he was an Apollo astronaut. It has brought him fame and fortune and he has traveled around the country inspiring adults and children alike. Do you really think he would admit that he was a phoney?
Also, when people are sick they generally believe that they will pull out of it.
d) What about all of those astronomers - they'd all have to be in on it. Nobody blabbed?
Astronomers merely observe the sky and interpret. They are not scientists who put their subject matter under controlled conditions to come to the truth of a matter --they can't. Astronomy is not a real science. Astronomers are fake scientists.
e) What about all of the people who build and sell GPS equipment, without satellites in orbit, GPS can't work the way it's claimed - but the people who write the software for these things would also have to be a part of the conspiracy.
The military built the GPS satellites and the military is publishing the spec.
f) Ditto satellite TV companies.
Do you really think that Dish network is building and launching their own satellites single handedly?
g) All of those ships, drones and aircraft that are claimed to be patrolling The Great Ice Barrier have to be in on the conspiracy - so do the people who build those ships, the people who supply them, the people who crew and repair them. So do all of the countries who have navies down there who'd have spotted them. So do all of the air-traffic control people who watch these aircraft land and take off in huge numbers.
Who claimed that the wall was guarded? Why are you making stuff up?
h) Navigation by the stars can't work the same way in FE as it does in RE. But sailing ships going back to the 1600's used this navigation technique...and their sailors wrote manuals about it - there are copious books on the subject. Every commercial shipping company and every navy in the world would have had to be a part of the conspiracy.
Celestial navigation works by looking at the North Star and gauging where East and West are based on that. For the South it involves finding the Southern Cross.
i) But hold on - the ancient Chinese had fleets that sailed around the pacific and indian oceans using celestial navigation - and they did this BEFORE they met the Europeans who were doing the same exact thing. This means that they both, independently, discovered that the world is flat and separately decided to collude on this (seemingly) more bizarre round-earth solution to whatever problem caused them to do this coverup.
The North Star is North in the Flat Earth model. To find the direction of North the Chinese just had to find the North Star. It's the brightest one. Simple!
j) Now add all of those sailors - not a single one of them came home from years at sea and told their wives and family that there was an enormous cover-up to hide the flat earth?
See above.
k) The pirates of the caribbean and south seas had to navigate by the stars. They LOVED upsetting the apple cart. Why didn't a single one of them expose the secret FE navigation charts and whatever stood in for a theodolite?
See above.