Via the Usergroup Manager (see screen
here) you can set the 'Maximum File Size' and 'Maximum File Limit' such that 'Maximum File Size' * 'Maximum File Limit' = maximum disk space you want to allow for users in that group. As for member specific galleries, there is nothing specific to allow the automatic creation of such categories. However, users can suggest categories since pro v.2.1.2 (see screens
here) where you moderate all category suggestions.