Mickey,
If you've bought a template system and are having trouble using it you could contact the seller with your questions. By the way, you haven't mentioned which template it is
That aside, I would suggest placing details you typically use directly in your template. This will have them pre-linked and any project customization will not affect any other project and the detail will retain the changes.
A separate detail file(s) works only if you don't make changes to any of the details. You can use the pmk solution that Eduardo suggests or make a copy of the detail file(s) for each project so changes will not affect any other project.
In your work environment >User Preference Schemes>More Options : uncheck the the 'do not launch new instance of archicad when placing a view onto a layout'. Don't forget to redefine the User Preference Schemes so this change is incorporated in your work environment.
You can set details and views to manual update if you are going to make changes to a detail or view that you don't want to revert to the original, but this is not good work practice. Instead create a separate instance of the detail/view as described above.
HTH
Erika
Architect, Consultant
MacBook Pro Retina, 15-inch Yosemite 2.8 GHz Intel Core i7 16 GB 1600 MHz DDR3
Mac OSX 10.11.1
AC5-18
Onuma System
"Implementing Successful Building Information Modeling"