Hi,
1. Yes.
2. Layouts cannot be created for now. You can however edit them via the menu Display>Views.
item box layouts on the other end (for the div layout) can be created by changing the name of the file when you edit them.
3. There is no tutorial. Basically all the show_block_* files each display a different part of the product page. Each show_* file is a different layout of the product page and the show file is the main view file of the product page.
For the listing, it's something similar, the listing view file is the main one, the listing_div, listing_table and listing_list are the main layouts of listings and the other listing_* files are the item box layouts.
The other files are for specific features (compare for the comparison view, carousel for the carousel system, option for the display of options, etc).
All the view files are overridable. In fact, even the classes, view.html.php files, helpers, can be overridden but it's more complex are you need to create a system plugin to override them:
www.informit.com/articles/article.aspx?p=1858258&seqNum=8