I know about usergroup. The thing is that PHPBB does not set default usergroup when create user accounts. If I want to add users to a usergroup, I have to add them one by one. There is no option in PHPBB to add all users to a usergroup nor a option to set a default usergroup when creating new user accounts.
In addition, I want to restrict each member gallery to 5MB. This mean the same user can post more photos in other sections. How does that work?