I have a PSD with a web design.
Every time I tweak the design, I need to manually copy different portions of the image, with different layer visibilities (for transparency) into CSS sprites.
How much can that be automated?
I used an automatic photoshop script once and worked well.
The concept is :
In your case, if you modify one image, you regenerate the global image and the CSS via the script and... that's it. Maybe you'll need to copy/paste the CSS in yours if you don't want to use the generated one.
I tried it with a few files and worked great. Then, I tried like ~600 pictures and then, you'll need a goooood CPU and patience ;) In this case, don't use it.
Wouldn't using slices + starting an Action that beguins marquee selecting (with snap to slices & document bounds on) all your slices one by one, but cropping to selection each time, and saving as png, ctrl alt z undoing till not cropped, selecting each sector, cropping..etc, till done with all sectors, then stopping the Action. In the middle you could hide/show any layer, as is the same file always, so shouldn't be conflicts... So you would load the action over your changed psd each time. Only thing I can think of is you actually need to change the slices borders. Or that... I did not understand you right...
Edit: if no need slicing, then a macro (action) that include only the hiding or showing the layers in the order you need, after all tweaks are done. As I say, I might not be understanding...