Hi @seanccc
First of all, the Thing Shape is not required whereas the Base Template is. We intended Thing Templates to provide the foundation for the thing with all the needed libraries, etc. If those elements were to change, it could result in underlying issues to your application. Thing Shapes were meant to provide functionality that can be shared across any number of templates.
For example, if you were a manufacturer of refrigerators, you would have a base template for each refrigerator model. But some features would be optional, such as an icemaker. This functionality would be provided by the Thing Shape and applied to only those models with the icemaker installed. Therefore, removing the thing shape in that case if the icemaker were removed would make sense. But removing the base template could result in a number of design issues.
To help you in your design, we have a couple of videos that may be helpful:
Expert Session: Designing the Data Model in ThingWorx
Expert Session: Developing the Data Model in ThingWorx
Please let us know if you have further questions.
Regards.
--Sharon