now that i am using the contamination-option of my queens a lot and due to my lack of fleet/points am focusing on inactive players, i wonder what's going to happen to them, if that inactive player gets deleted before my queens return? will they die and be lost - if so, how long will it take for an inactive player to be deleted? - or will they return with their loot as if they were filled completely?

If that inactive player gets deleted, your queens will return with their loot, which they managed to get at the moment

a player just asked in chat why the queens cannot be targeted in battle?

and how can we decontaminate our mines ? there should be an option to kill the queen otherwise it's pure game killer!

first: pls, tell me what unit did you use to attack the queen?
second: to kill the queen you have to destroy one level of the infected mine

as i said a player in chat room was saying that. so what are the ways of killing a queen? what ships work and what ship dont work?

You can kill the queen on the mine destroing one level of a building. You also can kill the queen in the battle, using of war fleet or defence