Members can create subcats depending on the permissions you set. If you allow them to create albums then they will be able.
If you need assistance please post your own thread and a detailed description of your specific issue so we can assist. Your posts are very general
Users can create albums if you have set in vbgallery admin to allow users to create albums in usergroup permissions and under your cat permissions you can specifically set whether or not to allow member albums in specific cats
Users if allowed to create albums will see links to do so when uploading.