Thanks for the detailed reply and here are replies to points 2 and 3.
2. Because the cms areas are on a blue background the css for the live site has been set for h1,h2 and h3 to be white text. When the client is using the offline editing window I would like to set a blue background and white heading tags. In the previous ckeditor3 I added these to contents.css, so my question is should this be set in contents.css or config.js for ckeditor4? Also I'm not clear about how contents.css and config.js differ in their capabilities.
3. See attachment for screen shot of the full toolbar used with inline editing on the local testing server. This is using IE 9 and is same on firefox. A lot of the toolbar items are greyed out and if I use the size dropdown to edit some text it then becomes greyed out afterwards. Maybe this is a quirk of a local testing server, I've noticed one or two odd things here and there.
This is a new question.
All the cms areas in the clients site are on a blue background with black text. When the client uploads images and adds them to the site they insist on adding a border to the image (tried to persuade them not to use a border but they still do) so this produces a black border on a blue background which doesn't look great. So my question is, can a default be set to produce all image borders in white, if so, how is this achieved?