How to handle parent and child pages?

Problem 2: displaying the 3 panels. Do I set these up as individual children elements? If so, how can I style each one differently as it loops through?

There are only 3 items. Don’t loop through them. Use get_posts() to place them in an array and then step through each array item:

$panels = get_posts( array() );

Fill the array() with the arguments to get those posts. Now $panels is an array of post objects. Step through them:

// First panel
// Do stuff with $panels[0]

// Second panel
// Do stuff with $panels[1]

// Third panel
// Do stuff with $panels[2]

To set up the post for use with Template Tags, use the setup_postdata() WordPress function. For example, to echo the post content for the first panel use something like this:

global $post;

// First panel
// Do stuff with $panels[0]
$post = $panels[0];
setup_postdata( $post );
echo the_content;

After all posts are done reset the from the main query:

wp_reset_postdata();

See setup_postdata() and wp_reset_postdata() for more examples and explanations.

For post thumbnails, read the codex article on Post Thumbnails for settings, details and examples.