I think you have most of the pros and cons right there. The other thing with the Z600 is it doesn't have any manual control over aperture and shutter priority available. If that's not important to you, you might prefer the convenience of the Casio.
The Z750 does have apperture and priority modes, but also a significantly higher price.
The A530 and A540 are probably the best you can do at their respective prices for cameras with full manual controls and good image quality.
But, if that's not important, I would suggest also considering the new Fuji F20. It also lacks manual controls (again available in the more expensive F30), but will give you image quality comparable to the A540, plus indoor shooting quality that beats both of those models handily, with the pocketable convenience of the Z600. Currently available (only in the last week) for about $230 US.