Assign custom class to post content images

Is possible to assign a default class to the images that are part of a post content? I have a problem with teh layout, this because the attached images insetred inside a post will break my bootstrap layout. I want to assign a default class so the user when add an image into the content will have the class assigned and the layout will not break.

Building a Featured Gallery component for Gutenberg

I’m building a Featured Gallery component for Gutenberg. As a guide, I’m using the existing Featured Image component from Gutenberg. Basically, instead of storing a single image id, the component stores an array of image ids in a dedicated meta field (of type array) called _featured_gallery.
Apparently, the getting and setting part is working, but I’m unable to show the grid of selected images (the featured-gallery-grid part in the code).
Any ideas? My knowledge of Gutenberg and React is limited, so I’m a bit lost here. Any help would be appreciated.

Display a custom name when the user has no name settle in his account

I’m creating a code that shows the First Name for logged in users, using a shortcode, but I noticed that if the user has no name settle, it will display a blank space. How can I set a custom name to show up instead of the blank space? Something like this “Hi >No Name<, please settle your name in your account.”

Understanding Redirects

I have a WordPress website that is working well. The website is shared hosted on a popular hosting site. It was migrated/transferred from a different hosting site to the current one (this point is mentioned as it may play a role in the answer to these two questions). The site has an SSL on the existing site and also had one the original site. I have changed the name servers at the domain registrar to point to the new hosting site.