[jpiech]

Thanks. Actually, it's easy to overlook this at first but splitting views also maximizes the working area, e.g.: (1) click the table toolbar and chose to hide it, (2) right click a given split view and hide row and/or column headings, (3) right click that view and hide the vertical and/or horizontal scrollbars. In the "View" menu you can also minimize the width of the splitter line. What's left in the view are only cells. You can have up to 99 individually resized and individually synch. views of various regions of the same worksheet or any other worksheet in the same workbook (View > Choose Worksheet) per window.

Re: the "Open with" menu for other file types, it should be done automatically once you set the file association (Windows might require the installation folder not to be account-restricted).