This is a common conservative argument when it comes to so-called controversial topics like vaccination or climate change (things that are not actually controversial, or at least shouldn’t be).
In the case of climate change, because it’s something I’m more familiar with and is easier for me to illustrate, there are people out there dedicated to “auditing” climate data - one example that comes to mind is a website where people investigate this system of temperature recording stations set up around the US which theoretically are uniform in design and construction and maintenance and so on, and set up in a uniform way so as to be accurate and reliable.
As you can imagine, with such a huge system, there will be variables at play. If you look at each individual station, you can probably find problems with each one. These people pick apart things like if the correct type of paint was used for the enclosing box, if it’s located too close to a heat island (parking lots, for example), and if the built environment has changed significantly since it was installed which would indeed have a noticeable effect on the data.
And you know… these are good questions to ask! This is why this type of argument is so persistent. The problem is, the answer to those questions is “it doesn’t matter” in a scientific context. This is hard to compute for most people who aren’t trained scientists. How can it not matter that the temperature recording stations are not 100% consistent? Several reasons. Even when the data is reported with full detail, this type of variance is considered and is included within the margin of error - and the interpreted results far exceed the margin of error.
Is there a possibility of legitimate problems beyond that - yes. Are fundamental, critical problems common, or reasonable to think exist in large projects like this - or that there’s collusion among the many different such projects that all corroborate the data - no. So here’s the real problem. What motivation do these people have? They are not thinking scientifically - it’s not peer review - they are politically (or religiously or whatever the case may be) motivated to find fault in the system, so they keep arguing that these things that don’t matter do, refusing to accept that they don’t.
So with your examples - they all sound bad. Does any of it matter in a scientific context, much less the public health context? Not really. They’re the equivalent of checking that the exact type of paint is used.
Interestingly in the vaccine context, arguments like this are essentially scaremongering against vaccines. In the climate context, the arguments are used to suggest that climate change “believers” are the ones scaremongering. But in both cases, it’s fearmongering by picking out things that are actually bad but which more importantly sound really bad, but that don’t matter.