As far as I know, I can either allow the user browse, read only, or full access. Is there any way to allow a user to do certain of things only? for instance, only to create volumes, or do a limitted modifications?
Sure. Clustered Data ONTAP uses a Role Based Access Control mechanism. You can create roles and assign roles to users in order to acheive what you wish for. Use "security login role create" command to create custom roles. Check the man page for more details.