Oscars and typhoons are loud in the standard database relative to other subs, and this has been left as it is, maybe to be addressed later.
Regarding the 65-76 torpedo launch, the use of weapons by the AI is something that needs more work for sure. Since the 65-76 has a longer range than the 53cm/ugst, it is possible that it didn't think it had a chance with the ugst, so it launched the 65-76, which is still listed as having asw capability, just reduced, same as the other russian wakehomer.
Thanks!
PS, the sensitivity of the tb-23 is in the middle of the tb-16 and the tb-29.