Theme Customizer not loading JS for live preview

i think your script is loaded correctly, same function is used in twentytwelve ( but your script is inside the iframe) but i can be wrong (dont know excactly how your theme is construct, maybe it’s a path related issue with multiple include)

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to see the change with no refresh you have to you use the ‘transport’ arguments in add_setting and get_setting in your customize_register function

$wp_customize->add_setting( 'my_setting', array( 'default' => 'setting_value', 'transport' => 'postMessage', ) );

This can be either ‘refresh’ (default) or ‘postMessage’. Only set this to ‘postMessage’ if you are writing custom Javascript to control the Theme Customizer’s live preview.

$wp_customize->get_setting( 'my_setting' )->transport="postMessage";