The AntsCanada Ant Forum's

Here is the Ant Care Sheet for them, (see more from the link in my signature) Prenolepis imparis **** Claustral-fully Queen Size- medium Diet- honey, sugar water, worms, some plants sap, fruit Care level- moderate to easy Polygynous-yes Aggressive-no Natural nesting materials-dirt, woodchips, leafli...

A species that you might be interested in is the Winter ant or Prenolepis Imparis. They are highly polygenous, they are calm, don't sting and they have really cool repletes that give them the name of the False Honey-pot Ant. To find them look around outside when in the early stages of spring. They u...

Also some ants wait until winter is over to lay their eggs such as Lasius spp, or Crematogaster spp.

Two weeks is a bit of time passed but it is also not a huge amount of time. I would first Identify the queen to find out if it is different, such as a social parasite. Then if it is I would release it since they are really hard to keep unless, you are up to a challenge.

any species of Phiedole.

there are some species of flies that are parasites and well, you know, kill queens. It's disgusting and sad.

Ants will eventually get used to the light. Usually ant keepers want there ants in the dark because it is more natural for them but, also one you get your ants accustomed to light, you lose a valuable way of moving them out of a old setup via shining a light on them.

according to antmaps.org
There are no species of the Crematogaster genus that lives in Sweden.

Also as long as there are not a ton of ants in there then the ants are going to be nothing more than extra gecko food.

Mites will usually come because of poor colony health and poor conditions, large healthy colonies have less of a chance to get mites.

I would suggest a Pheidole sp..

These ants grow at a mild to fast rate, nest underground, they are potentially polygenous and they also have majors/supermajors. I think that's everything on your list.