It can be especially helpful for debugging javascript files because AEM will combine multiple .js files and in some cases, minify the js making it very difficult to troubleshoot/debug. Here is a good post of some url tricks for AEM: http://blogs.adobe.com/experiencedelivers/experience-management/cq_...

Sorry, I thought you were talking about adding a workflow launcher on a sling:OrderedFolder. Where are you trying to add the functionality?

It's definitely possible, however I would use a servlet instead. When a thumbnail is generated on the folder, it will cause your workflow to fire. It gets ugly quick.