When I edit an appointment, the bottom part of the pop-up window is not visible. How do I remedy this?

That would happen when your screen resolution is low (everything looks big on your screen). When you click to edit an appointment or available time in the calendar, if the "Cancel" and "Save" buttons at the bottom of the pop-up window are not in sight, then you should be able to simply scroll down and bring them into view (check your browser settings if apparently you can't). You can also either zoom out the view in the browser (increase the view resolution) or click on the top area of the pop-up window and drag it upwards (while holding the click) until the buttons come into view.