I would suggest to step this up.
Currently its already part of the game, that fleet losses can lead to shortages of goods. How abaut possibilities to try to bribe trading fleets do divert goods. Either to get those to own planets in need or just to let them not arrive, where they should. Or to buy the stuff, which was actually for someone else.
The chance of success and the consequences need to be balanced or it could decivilisize core worlds really fast. Maybe a bribed trade fleet should get just half the impact of a lost one.
