I would like to export my preferences and object styles with no projects open and them import them on my team's machines so that no matter what project we create, we all start from the SAME set of defaults. When I open captivate and check both with no projects open, there is no ability to import/export. I know I could open a project and export, but then importing is an issue.
I'm using CP8 on a Windows 8.1 64 bit machine.
After a fresh install I start by editing the Preferences globally, that means by using Edit, Preferences before opening any project (like switching to Expert UI, default language, replacing feedback captions by shapes). There is indeed no way to import preferences from a specific file. I will do the same for some object styles (like creating a blank Highlight box for audio objects). You can only export/import from and to a project, same like for all Library assets.
However the Object styles: they are part of the default theme, along with their theme colors, master slides and skin. You cannot edit everything without having a project open. I would recommend to create a custom theme in a project, in which you have all the wanted object styles. Changing the theme colors (you can have a custom theme color palette) will change partially colors of the objects. Once you set that theme as default theme, you'll have all the object styles in the projects that use the default theme.
To transfer Preferences, custom themes to another machine, maybe this article could help you out. It was written for a different purpose, but you'll find the location of a lot of files that you could transfer in this post: