do not play with 1.3.7 - 1.4 is coming
I prefer not to do the curly multi-level user managed hierarchies of maps. Actually most of users give up even understandable album names as i realized it from my own experience with Gallery MOD (3+years...). Hope it will be enough for users to point to marker at their own maps by BBCODE. But is still subject to discuss...
As to user tags I think an extra tag named 'Photos' will be good. I can place all user posted photos to it. Automatically.
In version 1.4 'Maintenance' ACP section introduced... so you will be able set up the board maps with some king of import of users and attachments
I wrote some brief introduction to MOD functions, now it is in Russian, but... I know you can read