To be able to add/edit pages via Page Editor you must be logged in not only in Control Panel but also at the website as Administrator. And remember that you have two passwords – one for your uNet account (and logging in to websites with uID - the login page you see asks for this password), and another one for Webtop (and your website Control Panel if you have not set a separate password). 

You can edit, remove or add tags to entries on your page via YELLOW ARROW icon located at the upper right corner of the entry page which has a roll-over features.