I would concur Tim, however:
Lens distortion with sweet spot only applies to when you use a lens designed for a larger sensor. It doesn't apply to lenses specifically designed for the format (i.e. EF-S, DX, 4/3 lenses, Tamron's Di II series, etc.)
I would explain depth of field to be that a crop camera's depth of field should be calculated at the pre-crop focal length value. (since DOF is calculated by focal length, aperture and distance to film plane)
So yes it does have a larger depth of field, because using a 50/1.4 lens, your DOF should be calculated by using a 50mm lens rather than a 75/80 lens. Because a 80/1.4 (85 is the closest, I know) lens would produce shallower DOF at the same other 2 variables than a 50/1.4.
I'd also mention diffraction issues with a cropped sensor - how it shows up earlier, and this is why P&S usually have limited aperture values.