In the Classic Editor, it’s possible to split pages and add pagination using the following quicktag:
It isn’t possible to use this quicktag within Page Builder.
It’s only possible to clone pages if the source page has been built in the Classic Editor interface. If your source page has been built in the Block Editor you could manually clone by editing the SiteOrigin Layout block and then clicking LayoutsImport/ExportDownload Layout. In your new page, import the layout by inserting a SiteOrigin Layout block and then clicking LayoutsImport/Export and import the layout (JSON file).
The Live Editor is currently only available in the Classic Editor interface. The Live Editor currently isn’t offered within the SiteOrigin Layout Block.