Now I am in the middle of the theme development and have encountered some problems.
My approach so far is the following: I have a big container (position: relative) that contains the loop, with absolute-positioned featured-images. These images receive their position from their Post-Custom-Fields, with the values top, left and width.
The whole thing is responsive, because I am converting these values to percentages after the client has entered the pixel values.
The first problem with this approach: the main div is not growing in height, because the absolute positioned images are breaking the flow. I have solved this via a php script which waits for the highest value of the top-position of a div and uses this to calculate the total height for the container div.
The second problem with this approach is that the oldest posts are on top, followed by more recent posts at the bottom.
The third problem is that positioning divs with custom fields is a little to abstract, it would feel more intuitive and lead to better results, if there were the possibility to drag and drop the images.
Is there a plugin that could extend wordpress in this matter or solve on of these problems. Is there a better approach or other CMS that could solve this more easily?
Thanks a lot for your input, highly appreciated.