Registered Users Access to Albums

I am currently setting up my first Gallery installation (ver 2.3), and would like some advice on 'User Album Settings'. One of the things I want to use Gallery for is occasional photo competitions, and users will need to register for an account before they can submit images to a competition (so I know the persons name, and can contact them via email if they win).

Is it better to have a top level album, for example, called 'Competitions', and create sub-albums for each new competition, or should each competition be a top level album in its own right, with no sub-albums?

What I would like is for users to register just once, but be able to submit entries to new competitions (albums) as they arise in the future, whereas I get the impression they would need to register each time for a new competition, due to 'new registrations' only being allowed to create albums in a single specified album. Hope this is clear!

Any comments or suggestions appreciated.