I would like to increase the label area so that the label text doesn't get cropped. E.g. see red rectangle:
If you right-click on the chart itself (i.e. the central area) and select the 'Edit: > Axis > Axis area' menu item, it allows you to edit the area the chart occupies. You can drag it up from the bottom to allow more room for the labels on the horizontal axis.
This isn't exactly the most intuitive, and doesn't give as much control as you'd probably like, but should get you around the issue of text getting cropped.