This is a good question.
I wouldn't call them landmarks, because they are broader in definition, but they aren't so much zones in the traditional MMO sense. That's a tough call, as you want it to be clear to readers.
I would follow the nomenclature that Heroic Games is using, and call them Zones, and each ship level a Level. It may seem unintuitive at first, but we can put a small blurb about it on the portal pages.
Basically I'm saying that I trust your judgement; do what you think makes the most sense. That said, If it were only up to me, I'd follow Heroic Games.
As for the images, there's no great solution. Maybe we add a link to the full size on the page? http://www.wikidot.com/doc-wiki-syntax:images