Or please tell me, Universe uses a random engine for techtrees and in my next game I'm able to use torpedos again or at least the good old Concussions or Assaults (The second appears in my techtree, but it is the last thing I can research and definitely too late in the game) .
Universe does not use a randomized tech tree. The tech tree is the same in every game for every faction, outside of a handful of species-specific technologies (PulseWave Cannons, Shakturn FireStorms, Megadensity Fuel Cells, ShadowGhost ECM, Raptor Targeting, Velocity Drives, SwiftVectors, TurboThrusters, Starburners, NovaCore Reactors, and Megatron Z4s; the three superweapons do not appear in the standard tech tree and normally cannot be researched or obtained). Unless you have not bothered researching anything out of the missiles or torpedoes trees, there is no reason why you should not have access to any long range weapons better than Seeker Missiles. The Torpedo branch should be just above the Fighter branch and research in it is required for the Advanced Fighter Bay, while the Missile branch is located just below the Boarding Pod branch (which itself is just below the Fighter branch) and research in it is required for improvements to boarding pods and missile bombers.
Also, if you have ignored those branches of the tech tree, you cannot possibly have researched 'almost the entire tech tree,' as those two branches contain or are required for something like 30% of the techs in the Weapons tree.
If you're using a mod, then the above might not be entirely valid.