I'm in FM 12 on Windows 7 and my coworkers are on Mac's. We have a primary office copier/scanner/printer.
There is a script step "Print Setup" that opens the printer dialog box that should give you access to that printers properties. For example our Richo MP5002 opens in the print dialog box, I select Properties and I can turn enlarge/reduce on then set a Zoom setting of 25-400%. I save the Print Setup script step and those setting will be used by anyone using that printer.
Since that page setup is for that printer profile though - I don't think it has an impact if you select a different printer.
The better option is to go into the layout and design the layout to fit on a standard page (portrait or landscape) sized to print with margins set in the Layout Setup dialog box. That would make "Print Size" independent of the machine running the solution and the printer to which it was going.
You can also have an "input" layout that the user interfaces with and then a "print layout". The user uses the more comfortable interface for data entry and you script switches to the "print layout" when generating paper or PDF output. You make it easy on the user by having a "Print" button or printer icon on the input layout. Then a print script handles the page setup, layout switching, and printing and after that returns the use to the input layout.