You have created a new section in system configuration under the Catalog tab:

How do you restrict an access to the section using Magento ACL?

The module MyCompany_MyModule provides custom admin interface pages.
Access to these pages should only be granted to specific users.
You add the required configuration to the module's acl.xml file, but the setting does not seem to work as expected.
How do you visually check if Magento evaluates your ACL resource as expected?

A module declares the route:

What is the layout handle of the storefront path /custom/feature/?

You are adding a new menu item to the admin backend which will link to a custom backend page.
The declaration of the route:

What do you specify as the menu item action attribute value so it links to /admin/mycompany/mymodule/?

You added a new constructor argument to an existing action controller class.
When you reload the page you get a PHP error that the wrong argument is passed to the class.
How do you fix this?