When entering text in the body or an article, how can we access custom classes? Is there a WYSIWYG editor that can be used in the panel or do we have to dig in the HTML of the post to have more choices of formatting than those offered in the menu?
Thanks.

Through the use of an Extension you can add a WYSIWYG editor.

A list of extensions can be found in the Wiki.

It should be noted that the reason why we’ve never offered one installed by default is because there hasn’t been an editor that works reliably across different web browsers on different computer platforms, due to inconsistent JavaScript support.  Fortunately, all major browsers have improved considerably in recent releases, so this might not be an issue in the future.