I am working on an already set up site where the custom theme was created very much manually and the head-region markup, incl. logo, main menu, user menu, etc. are manually rendered with a particular set of CSS based on twitter bootstrap. The admin theme was left alone, so it doesn´t have those head-region markup. But I do want admin pages/forms to seamlessly be rendered with the custom styled head-region. I tried isolating the css used in the head and added it to the admin theme´s page.tpl. This proves quite disastrous, since a hell lotta css conflicts come up, esp. because of bootstrap.css.
One lousy way would be to add element specific resets. But perhaps there´s a way to shield/wrap the head and the form so that they can still coexist on the same page with their own baggages of css+js?