You may want try these solutions to your concerns.
1. In order to change the Page Orientation to landscape and change the paper size to 8x11 size, just go File>Print>Preferences
* To change the paper size, under "Paper Options", change "Size is:" Legal
* To change the the Page Orientation just click on the image (with H and bar graph) at right side. Then click OK button to save the settings. Or you change it also in File>Print>Print Preview, just click the 3rd icon from the left, on the upper left then Print.
2.Print Selection is not yet implemented in Modeler 12, but this feature has been raised for the next release.
Hope this helps.