You can re-use workflows as much as you'd like but you need to build them to be generic.  If your workflow explicitly references a SmartObject then it's going to keep using that SmartObject.  There's no way to make it reusable if you reference that SmartObject over and over.

Other reusable components could be SmartObjects, ServiceInstances, and SmartForm Views.  But again, they have to be built in such a way that they are reusable.

K2A,

 Make when adding permissions to a workflow that you check the box that will allow the workflow to be reused. Our reusable workflows are generally basic in nature and usually do not contain more than a single user task or an email. Generally we use these in a forward loop to start multiple workflows when several people are required to work a new task. Unfortunately if you add an item reference to a workflow you will always have that item reference. 

Another idea is you could build a dynamic form where the user can choose the type of request from the main form. Based on the selection is the view that becomes available for them to complete. You could then create rules within the outcomes of your workflow to change the path or the participants based ont he form selection.

Thanks,

Bryan Peters