I am trying to decrease the size of my app as much as possible because my app will have a lot of moving parts. Will minimizing files and deleting files that are not used in the app decrease the size? When installing a framework, you normally get more files than you need.
When your app is delivered it is delivered as a ZIP file (APK == ZIP, IPA == ZIP, XAP == ZIP, etc.). So it is compressed. Of course, images and similar objects are already compressed, so there is no decrease in size of these objects.
Certainly deleting unused files will help. Does your project have a unique www directory in the project, where the sources are located? This will help, especially with future releases. See this FAQ if you need help converting your project to one that contains a www directory > https://software.intel.com/en-us/xdk/faqs/general#www-folder