In order to delete a podcast, follow the instructions below:
If there is any episode inside selected subscription or folder, all available episodes are deleted or thrown into the trashbin if it is enabled.
In case of deleting a folder, if there is any subscription under that folder, those subscriptions are moved up in the folders hierarchy.
If there are downloaded episodes inside, Ziepod asks you whether you want to delete those downloaded files, as well. When episodes are deleted and thrown into the trashbin, their downloaded files are not preserved. So this is the where you have to decide what to do with downloaded files.