Charissa,
The view option is set in the template, by default called topic.template.fm, not in the application definitions in structapps.fm. If you have write permission, you can modify the existing topic.template.fm by changing the setting there. That's all you need to do if you are willing to modify the distributed file.
If you would rather not edit the application files that come with FrameMaker, you can make a copy of topic.template.fm (changing the name if you like, perhaps to something like topic.template.modified.fm). If you decide to do so, you'll need to tell FrameMaker to use the new file. That's where editing the application definitions becomes necessary. Application definitions specify a few options, primarily identifying various files that are used to open and save XML documents. Whenever you start FM, it reads two application files, both called structapps.fm. The global application file is in the FrameMaker directory, probably in Program Files. You also have a personal structapps.fm, which is in C:\Users\<your user name>\AppData\Roaming\Adobe\FrameMaker\13. You can put modifications of the global application file in your personal file. You can also define additional applications if needed for your own projects. FM reads the global file before reading your personal file, and the definitions in your personal file override and add to those in the global file.
If you decide not to change the distributed template, you probably won't want to change the distributed global application definition file either. That's when you can copy the definition of the DITA topic application from the global structapps.fm to your personal structapps.fm and change the name of the template file there.
Note that changes to either structapps.fm won't take effect until you either restart FM or use the StructureTools > Read Application Definitions command. This command must be issued when the structapps.fm file you want to process is the current file.
--Lynne