You have successfully installed Alfresco Share and now you want to expose Share on internet so that you can collaborate with external users. But you do not want them to access certain pages, like the repository page, for whatever reason you have. First thing you do is to remove the button or menu from the toolbar, having looked at the instructions found on the wiki about Share Header.
Alfresco just released Alfresco Team http://team.alfresco.com. It fills a gap between the unsupported Community edition and the for SMBs rather expensive fully supported Enterprise edition. It is a release with lots of new features, you can read all about them on the team site. This is instead about the limitations put into this release.
Alfresco Share use as standard TinyMCE for inline editing of html files. I needed to customize the editor for a project, but the TinyMCE editor used has some specific Alfresco customizations. Instead trying to understand the Alfresco code, I started from scratch and used the CKEditor, ckeditor.com.