"So long story short, is there any way to resolve URLs and fix them on entry and exit? " -
at the moment
there is no automatic way to resolve this links.
Your current approach is good. The only thing left you need to do is get the editor's content on the server and replace the string "http://ip.address" with nothing(""). This way all the links will become relative to the server (e.g. "/content/image.jpg") and will work after you change the server's address. Note that you need to do the change on the server before you save the editor content (either in a page or in a DB).
the Telerik team