Custom CSS Not Taking

Right. Thanks for noticing this, it seems its a known issue already (https://wptheming.com/2011/05/options-framework-0-6/).

I guess i will just remove all kinds of sanitization for <textarea>‘s.

If you do not want to wait for next version; just open your ./inc/_admin-init.php and add the below lines to the end of the file:

// Remove all sanitization for textareas
add_action('admin_init','optionscheck_change_santiziation', 100);
function optionscheck_change_santiziation() {
    remove_filter( 'of_sanitize_textarea', 'of_sanitize_textarea' );
    add_filter( 'of_sanitize_textarea', 'custom_sanitize_textarea' );
}
function custom_sanitize_textarea($input) {
    return $input;
}

PS: For such css customizations personally I’d recommend using the override.css file. Just turn on the Override.css option ON under Dev tab and add all you css overrides in /rsc/css/override.css file.

Marking as resolved, report back if you have further questions. Thanks for your feedback

I tried tackling this from another approach, which was to create a child theme. Doing this killed formatting for both the child theme and the main theme. Even deleted directories for both and tried to rebuild from scratch, all to no avail.

I have to check that, never tried using it by actually creating a WP child theme.
On a side note; the theme has its own sub (child) file function eo_get_template_part() which currently reads from module files (carousel,highlight etc.) from ./child/default/inc/modules file; so for example if there’s a copy of carousel.php child\default\inc\modules\carousel.php that one is read instead of the ./inc/modules/carousel.php
However i havent used that function for other includes just yet.

But like i said; you should better use override.css file for css overrides, it’s loaded at the very end of the </head> so it overwrites everything else (base files, child themes, inline custom css etc)
Or you can remove the data sanitization from textarea like explained above