Dividing into four steps:
1. changing file name/path -- well, it's not really done that way. From within ID you would simply save your document into the new location. See Adobe's JS Guide for the details (document.save).
3. Saving on the server: see 1.
4. Exporting as PDF: Adobe's JS guide will help you there as well (document.exportFile).
Oh, and point 5: a UI. Either use regular InDesign scripting (useful for quick-and-dirty projects), or dive into ScriptUI (worthwhile for something looking like a pro dialog; coding manually is a bit hairy, but on Windows you can a use specific design utility such as Rapid ScriptUI -- http://scriptui.com).
Thanks for the help... I will start there.