The astronauts do the maintenance. Seals can last a long time before replacement, you don't seem to understand that its not the absolute pressure a seal cares about but the differential pressure across it. 15 psi or so is not very much pressure difference to seal anything.
- Why do you need back pressure to vent something? All you need is a differential pressure.
There is a grounding system on the ISS, do you understand electricity and what a ground is? Replacing components may be hard but they do it.
These are designed not to break, crack etc. when exposed to these conditions. These are not as extreme conditions as you want to believe. I was on a sub, did maintenance on a sub, the hatch seals never needed replacement the 4 years I was on it. These had to seal with over 400 psi differential pressure, the kind of pressure the ISS does not have to deal with. The reactor pumps have seals that are exposed to 480 F temps and 2000 psi differential pressures.
It seems that just because you don't understand how these things can be done then they cannot be done. That is fallacious. These have been demonstrated to work since 1969, or I guess that is another conspiracy theory you must believe in right? No moon landing.
Some of these people have been confirmed to live at the same time the challenger blew up. How do you explain that. This sullies their memories by calling them liars without sufficient evidence.
You are making the claim it is up to you to figure that out.
Why are most flat earthers so combative? I believe it is because they know they are wrong.