never tested it but your photos should remain unchanged. the sets are, more or less, search functions... a set of rules.

i'm certain you don't have to worry but you could always create a dummy set and see what happens.

metrognome is right: sets are just a saved search (that's why the are called *smart*), a dynamic filter with a name. They might even contain other people's pictures, not only yours.

So photos are definitely not deleted when you remove a set. (Photos can not be deleted on Zooomr anyway, but that's another topic.)

thanks!