ikaring

I think the simplest way is to add 100% width div with the image as a background image.
Put div with class name like ‘hero’ right before div#content like so;

<div class="hero"></div>
<div id="content" class="cf site-content">

Add css styles like:

.hero {
  background: url('http://simconnection.net/wp-content/uploads/2015/09/12593991_359206020870201_3347543352591936245_o.jpg') no-repeat center top;/* Set path to your image */
  background-size: cover;
  height: 400px;/* Assign any height */
}

Hi. It’s just an example code since I don’t know desired output.
If above code blocks do not make sence to you, why not consider to use the plugin you mentioned.
That should be much simple and easy, I guess.

You dont have to use slider.
Just build $output for your desired html output.
In above tutorial, $output is defined from line 40 to 100.

For example, if you use the caption field as link url in each images, it can be retrieved by:
$link = $attachment -> post_excerpt;

And then add to $output around line 62, like:

$output .= '<a href="' . esc_url( $link ) . '">';
$output .= "<img src=\"{$img[0]}\" width=\"{$img[1]}\" height=\"{$img[2]}\" alt=\"\" />";
$output .= "</a>";

You can customize the output of [gallery] shortcode.

http://webdesignforidiots.net/2015/02/customizing-the-output-of-the-gallery-shortcode/

Sorry to be late, it was Japanese holidays^^

I suppose your code is on page template, instead of single post template.
If that is the case, pls replace

$paged = ( get_query_var('paged') ) ? get_query_var('paged') : 1;

with

$paged = get_query_var( 'page', 1 );

It is ‘page’ instead of ‘paged’.

Below is just for your info:
Actually I didn’t know that get_query_var can have default value in second parameter.

$paged = ( get_query_var('paged') ) ? get_query_var('paged') : 1;

can also be written as

$paged = get_query_var( 'paged', 1 );

http://codex.wordpress.org/Function_Reference/get_query_var

Your theme Orvis seems to be of WordPress.com not WordPress.org.
That means you can not customize theme unless theme option is provided for the feature.

Congraturations!

Managing title Results should be much easier.
Split the line
<?php if ( $the_query->have_posts() ) : while ( $the_query->have_posts() ) : $the_query->the_post(); ?>
to

<?php if ( $the_query->have_posts() ) : ?>
// put title Results here
<?php while ( $the_query->have_posts() ) : $the_query->the_post(); ?>

As for pagination, there are many plugins to handle. I usually use WP-PageNavi.
https://wordpress.org/plugins/wp-pagenavi/

Cheers.

I have tested myself.
Please replace the line below.

$athlete = wp_title('', false);

with

$athlete = single_post_title('', false);

I found a strange point. Please check if server data is updated.

In meta_query, there should be ‘key’ and ‘value’, instead of ‘meta_key’ and “meta_value’.
["meta_query"]=> array(1) { [0]=> array(3) { ["meta_key"]=> string(14) "result-athlete" ["meta_value"]=> NULL