So ... is there any trick to mission 5? I have to escort two bombers (i guess they are bombers) and cover them while they destroy two raiders. But no matter what I do, those bombers are evading and shooting with their guns and not firing any torpedoes. After a while raider take out my bombers and my orders change to destroy those raiders myself ... with my light fighter 😭

It's like my bombers don't have any torpedoes at all...

Your question is discussed with a lot of hints given in the "Vage Invasion" thread. The mission is definetly doable, and yes, you can save both ISS pilots.