Comment: header_title

That is a lot of questions. Let's start with the very first one.

The background image of the header panel is loaded thanks to following lines of the .ccs file:

#header_panel { /* comes before everything */
	background-image: url('images/header_background.jpg');

One thing you can do is to rename your own file 'header_background.jpg', and to save it into the sub-directory 'skins/tatodskeleton/images'.

Another option is to place your image in the directory, and then mention its name in the .css file.