Expert field template has broken styles in the admin

I'm not familiar with best practices for configuration forms within an ajax, but (and I'm hesitant to even suggest this) perhaps putting it in a table would help? At the very least we could add in zebra striping to differentiate the rows?

@swentel also noted this problem over at #1931216: Hide unnecessary fields in expert field template (which is an issue that could certainly clean this page up as well).