The other issues are not as big of an issue. One is that the Cnt ++ shortcut does not zoom in, but the zoom out shortcut works.
Zoom in: Control key + 'plus'
Zoom out: Control key + 'minus'
If you have a mouse with a scroll wheel, it is most convenient to use that.
The other issue is that there does not seem to be a way to draw a preview window. When I go the preview window and enter a new preview it gives a dialog window that asks for the coordinates of the preview window.
Verify that 'Show Previews' is selected in the PREVIEW menu. Then press Alt + N for creating a New Preview which is done with the mouse. If you want to correct the coordinates you can do so immediately with the mouse (press the left mouse button inside the green rectangle and shift to shift the whole preview, press the left mouse button on a margin or a corner and shift to enlarge/reduce the size of the preview). Alternatively you can select 'Modify Preview' and alter the numbers.
I find it most convenient to have the Preview Tool Bar active, so you directly see the symbol for e. g. Show Previews without having to go to the menu. Some more very helpful Tool Bars are:
Image, Display, Mode, Zoom, Preview, Mask, Screen Transfer, View Selector, Workspace Selector, Position, Readout and Information. The active Tool Bars are set in the VIEW/Tool Bars menu. I recommend to select these.
Bernd