How can you render a text on a page using only layout xml?

You need to add a new text attribute to all products in the Magento store. When this attribute is displayed on the product page, its values must be different depending on the selected language.
Keeping simplicity in mind, how do you add this attribute?

During a code review of a module MyCompany_PaymentCurrencies you see a configuration field declared in the file etc/adminhtml/system.xml:

What is the consequence of the attribute showInStore being set to 0?

You are working on a custom web API endpoint and have configured it in etc/webapi.xml.
This config is cached as part of the config_webservice cache type.
Keeping performance in mind, how do you refresh the cached version of this config using Magento CLI?

You are working on a project that contains a million SKUs. The merchant has requested the product view page to have a custom color schema and page layout depending on the product price range.
How do you implement this, keeping simplicity in mind?