If CSS is not outputting inside wp_head, it may imply that they’re not being enqueued correctly. See here for more info. Maybe they’re hardcoded in the theme file? In header.php?
As for scripts, my guess is that they are being enqueued and set to trigger during footer actions, so the fact that you’re not calling wp_footer() means that those actions never fire.
If you cannot edit the footer.php template file to remove all the unnecessary output, while still leaving wp_footer() the code above, then at least trigger the usual actions manually, like so:
// ...
</div><!-- #content -->
</div><!-- #container -->
<?php do_action('wp_print_footer_scripts'); ?>
</body>
It’s hard to tell if this will work, because it can depend on how the scripts are enqueued, and it varies wildly from plugin to plugin (especially if the original coder doesn’t follow WP coding standards), but hopefully it’ll lead you in the right direction.
Edit:
If you need to add dependencies to your scripts, like jQuery, to make sure those deps are enqueued and loaded before your own, do this:
wp_register_script('product-customize-preset', plugin_dir_url(__FILE__).'js/preset.js', array('jquery'));