Yes - that is a custom mod - you will have to talk to your developer about it.
I can't advise on the fck editor installation - perhaps someone else can comment or you can start a new thread with your specific question.
For static pages - you might consider always placing your images in skin1/images, then check "Parse Smarty tags in the content of embedded page" and reference the images with <img src= {$ImagesDir}/
That will always provide the correct path, and work for both http and https.
But - this would be done outside the WYSIWYG, so it requires a little more understanding of uploading the image files directly and editing html code - so it depends on your comfort level.