Are these FZ200 shots more or less noisy than you would expect?

Bottom line, the lens and the sensor at full zoom capture an image - and you can't get a more highly magnified image except by adding an extension lens.

You can crop the sensor (EZ does that) so it "looks" more magnified, but you're just showing the user fewer pixels. You might find it useful because it makes composition or focusing or exposure easier, but beyond that it's the same sensor and lens as before

You can take the cropped sensor and expand the image digitally in the camera, so you save a "12mpx" image - but you see lots of artifact. This is what happens with iZoom and digital zoom. It's irreversable - There's no way to go back to the simple cropped sensor.  Seems to me that you're much better off doing this sort of manipulation in post processing - if you need to - where you can work with a copy of your file and toss out the result if you're not happy with it.

My bias (now that SPPro5 is available) is that raw images are better suited to heavy postprocessing, but you can certainly do the same with JPGs.  The important part (again, IMO) is to avoid creating JPGs processed using the iZoom and digital zoom settings.