This is basically a request to include the functionality of https://www.drupal.org/project/html_title into core, to allow portions of the node title to be italicized/bolded/sub-superscripted etc.
Drupal node titles are restrictive and do not support italicized text or superscript text (e.g., Book titles, trademark symbols). The HTML Title module allows a limited set of HTML markup (em, sub, sup, b, i, strong, cite, code, bdi, wbr) to be used in node titles. It filters all other markup from titles to prevent XSS vulnerabilities or irrational nesting (e.g., links within links).
Recent comments
A simple way — use Field Group to create a container for fields https://backdropcms.org/project/field_group and CSS Flex оr Grid to alignment.
Layout also for /node/add/ forms?
Yes. The are several ways to do this: Install Mail System and select "Testing" for delivery in admin/config/system/mailsystem Install Maillog / Mail developer...
Prevent Backdrop from sending emails
The short answer is no, you can't theme forms or change their layouts through the UI. There is a ported version of Display Suite, which has a submodule called Display Suite Forms that allows you...
Layout also for /node/add/ forms?