All true (though the proposal is for gaseous oxygen), which is why a long pipeline at the south polar site seems strange to me. Even if the O2 production must be done at a fair distance from the habitat, I'm wondering why it can't be buried in regolith over most of its length, which would partially mitigate some of the issues you mention, not to mention providing protection from meteorites.

OTOH, if you can learn to manage the issues you're identifying here at this site, you do open up a lot of the solar system (asteroids, moons of Mars, airless bodies generally)...