I have used Confluence since 2006 and I have to say that the worst desicion you've made was removing the wiki markup editor. Could you at least fix the "insert wiki-markup" macro so that it would be possible to edit content using the markup syntax? Now the wiki markup box disappears when writing something into it...
e.g.
1. Insert a wiki markup macro in to a page
2. Add content into the wiki markup macro (for example !image_file_name!
3. Save the page
4. Edit the page
5. The wiki markup box would still be editable, e.g. to make the image as thumbnail, simply add !thumbnail| before the name of the image file.
Please, bring the markup back!