well - firts thing - you need to forget about NPrinitng 16 concept and NSQ files - this does not exist anymore.
NPrinting Designer is installed on Developers machines and as you pointed out they can develop reports by themselfs - BUT NOT ON THE DESKTOP!!!
The main difference is that Designer is getting opened from NPrinitng admin console and does not work as standalone program. It is only an extension to a server, so templates are still auto-stored in repository on server side.
Designer then is basicly a designer client for a server side development. Whatever templates you are going to build with designer they will be automaticly stored in dedicated folder for dedicated NPrintign application. There is nothing you store localy.
This cannot be changed and this is how NPrinitng 17 is designed. When you get more familiar with it you will understand that all other components starting from NPrinitng Application, Connections, Filters, Conditions, Reports, Task Users, Roles and Groups etc.. all is server side and Designer is used only to compose templates which still get automaticly saved and linked with app & connection in right place on the server...
Just want to add here - that to be able to open designer you need to have a connection to NPritning server and it needs to be exactly the same version as NPrinitng server!!!
When applicable please mark the appropriate replies as CORRECT. This will help community members and Qlik Employees know which discussions have already been addressed and have a possible known solution. Please mark threads as HELPFUL if the provided solution is helpful to the problem, but does not necessarily solve the indicated problem. You can mark multiple threads as HELPFUL if you feel additional info is useful to others.