Need to know the most essential JS and CSS files for a Drupal 7 page
You can achieve this by making your module load your own html.tpl.php and in that version of the html template, you simply remove references to styles and scripts.

&lt;?php print $styles; ?&gt;
&lt;?php print $scripts; ?&gt;


For a viewer, you can probably do without the reams of CSS cruft that is loaded by default and add your own bare bones css &amp; js either through a hook or by including it in your custom html template.

&lt;?php print $path_to_your_reader_styles; ?&gt;
&lt;?php print $path_to_your_reader_scripts; ?&gt;