I'm not sure, but paid accounts can create Layers? It gives more possibilities, like importing other basic LJ layouts.
but what I REALLY want is the welcoming-X picture in the sidebar above the navigation links rather than tucked off to the side, with the sidebar being the same pale blue that X is currently sitting on.
It can be done, but not with the kind of layout you picked. IJ doesn't provode a CSS file for it, and I couldn't find any overrides online. Advanced customization can be done more easily with layouts using CSS. I think current layout can be imitated using another base, like Bloggish- with the sidebar as you want it. Should I look into it? (I don't know what kind of extra options a paid account has, though)