Oh and according to this thread you can alternatively use the ‘featured image’ function to assign a specific header image:
http://wordpress.org/support/topic/want-a-different-header-image-on-each-page?replies=11
for Q1, maybe this plugin will help you:
http://wordpress.org/extend/plugins/wp-display-header/
I used it and it works great to assign custom header images to specific posts or pages.
