I completely agree with your reasoning, I'm looking forward to the gtk-3.0 move and future theme efforts, I, and many others, strongly appreciate your panel hack for the internim.
One of the things I'd mentioned turns out to have actually been a bug.
When installing the proprietary ATI driver (fglrx), Compiz stops rendering the window decorations properly for third party themes (all themes but Ambiance and Radiance, strangely.) and the window decorations appear frozen until resized.
This meant that when using your theme (I hadn't used the regular elementary theme long enough due to the unthemed panel to notice the problem) I couldn't see the prelight mouse-hover changes when moving my cursor over the window controls. I thought it was a Unity problem or some new window control system Unity used (due to Ambiance and Radiance working) like the panel theme itself.