Theme development

Can someone explain to me the strategy of the theme.library.yml file for a theme. I am not understanding where the words "global-styling" is coming from or system/base. I have read SMACCS documentation but cannot wrap my head around the naming convention in the theme.library.yml.

At some point near the end of development for my Drupal 8 site, any NEW block placed in a region isn't displaying or being output to the DOM. I place the block in a region, define what pages to display it on, click save blocks and yet nothing shows. I've tried clearing cache multiple times, but no dice.

All of my other blocks are still working (from before this started happening) but I'm afraid that if I remove them and try to re-add those blocks, they aren't going to render anymore. Any ideas?

I have a function that have this

<?php
        /*Render de the the select of branchOffices of a Bussiness*/
        $_select_branchOffices = drupal_get_form('_user_management_get_branch_office_form', $business_id);
        $select_branchOffices = drupal_render($_select_branchOffices);

       $html = theme('link_user', array('select_header' => $select_branchOffices));

       return $html;

I have a .tpl file where there are this

I would like to check which values of checkboxes (field_list) are selected.
Node has list field with three options [checkbox].
I have tryed to debug dump(content.field_with_checkboxes) but after that drupal render blank page

I'm familiar with the Drupal 8 theming API, including the hook_preprocess_HOOK, as well as all of the theme template suggestions available when Twig debug is enabled.

However, what I would love to be able to do - is to control all of the individual fields and optional labels for a node - inside the node--tool--full.html.twig template (my content type machine name is 'tool')

I also know that I can simply leave out the call to {{ content }} in the Twig template and call fields individually like this...

Hi, did somebody can say me if is there a drupal 7 module that can control the visibility region on a specified page/view ?
In my case i've 2 hide the Primary Region on a specific views using a bootstrap 3 subtheme.

Thank u.