1. There isn't one "safe" resolution — every client has different computer equipment practices, and therefore different screen sizes. On top of that, different clients may have different experience expectations for how much of their screens any one application takes up; some users will expect an application to fill the screen, and others will expect FileMaker to be one window among many. But if you insist, one firm I worked with settled on 1280x800 as the least common denominator target screen size.
2. Yes. Personally, I recommend teaching users how to use the zoom controls themselves rather than being so controlling with the programming. (I have a big screen so I can see more information at once, not so I can see the same information larger.) Read the FileMaker Help documentation on the Get ( WindowDesktopHeight ), Get ( WindowDesktopWidth ), and Get ( WindowZoomLevel ) functions and the Set Zoom Level script step.
4. I'm not exactly sure what you're asking. Are you asking if there's a way to set the window size on FileMaker Pro (including Advanced) so the window content area is the same as it would be in FileMaker Go? If that's what you're asking, yes. I wrote a module for that that you can copy & paste into any FileMaker file you're working on.