Quick Game Maker question:
If I have a ds_list created by object_1 in room_1, and I change rooms to room_2 without destroying the list, the list is still occupying memory with no way to access it, right (unless the list id is stored in a global variable)?
That´s right, you can check it with ds_exists(lstName, ds_type_list). The list should also remain accesible if the object is persistent.
The first thing I always do when I create a ds structure is write the code that will destroy that structure.