We'll have to deal with those based on reports and set them manually I guess, much like when someone other than me uploads my map to Maplantis and it becomes automatically open sourced.

maybe you should default to "licence type unknown" or something similar unless/until someone (submitter or author) marks it otherwise?

Will the description be set up how it was in the old SEN, where it resembled a forum post?

Also, I'm not sure I like the idea of any registered user editing things in the DLDB. Someone could do a whole lot of damage before he's caught and banned.