As a side note, I recommend Exec-PHP over other WordPress plugins that allow for PHP in posts. Hefty documentation, and works quite well when you don’t mess up yourself.

And it turns out the “odd CSS consistency” is not really an odd CSS consistency. It’s something to do with the fact that I can’t embed PHP directly in pages based on the default template, so I had to revise the theme’s Archive template instead, which presumably is leaving space on top for links that will never appear (or something). I found some plugins that should make my CSS work on a normal page, but they all manage to screw up the actual results somehow. Still working on this, and comments still welcome.