Yes indeed, in fact your first bullet point does that. By stitching a panorama you are simulating a larger sensor.

The effect works best when you use a telephoto lens and create a multi-row panorama with approximately the same aspect ratio as a regular photograph. This is sometimes referred to as the Brenizer method (after the person who popularised the technique) or a "Bokeh Panorama".

To convince yourself this works, thing of the last time you saw a telephoto shot (say 200mm) with a sharp background? Never (unless the BG was within the DOF, unlikely unless you shoot 1/128). By stitching several telephoto shots together you get the field of view of a wide lens, but a blurred background in every shot, hey presto shallow depth of field! Stan gives a very good more detailed description of the technique in the answer to this question:

What is "bokeh panorama" (also called the "Brenizer method")?

The opposite also works, if you want to simulate the deep depth of field of a small sensor camera use a very wide angle lens (like a 10mm) and crop a tiny bit out from the centre of the frame and you'll get the equivalent of a slight telephoto on a crop body (albeit at a much lower resolution).