The recipient normally is the person which is logged in, during the NAST-Entry is saved.
I know, there are several options available in the customizing, but I'm really not sure, so perhaps you can work through the official help located here:
Output Determination (SD-BF-OC) - SAP Library
The "print immediately" option cannot be set to the user-parameters via customizing. I think you have to use a userexit in the messaging to put some lines in there to make this work, but also please work through the official documentation.
If you doesn't find a solution, I think this space match better for such a question:
Here in Output Management is more the developing view located, sry.
~Florian