What does 'Range' do in the menu element?
The 'Range' in the menu list item element sets which list items at the current level the settings should apply to.
Acquia Cohesion renames to Site Studio from version 6.2. Tell me more.
The Youtube video embed is responsive so it should expand to the width of its parent. If you do need to set a width you can apply the Width CSS property through the Style Builder.
The WYSIWYG (ckeditor) adds a paragraph tag around the text within the block quote. This causes it to inherit the text size of your paragraph base style.
Custom styles are CSS styles for classes.