The (illegal) coffee plant in the hydroponics bay was mentioned in the pilot Babylon 5: The Gathering (1993), but belonged to Lt. Cmdr. Laurel Takashima, the character who was replaced by Ivanova when the original actress was no longer available.
The symbol branded onto the Minbari victim's forehead is the 'Hermaphrodite' symbol: the cross and arrow joined at the circle.
Episode title, 'The War Prayer. In 1905 Mark Twain wrote a short piece, only a few hundred words, titled 'The War Prayer' but feared having it published while he was alive. It was an anti-war piece intended to counter the witless rhetoric of war mongers by pointing out that even the enemy is human and everyone suffers and loses in war.
This takes place from April 3 to April 7, 2258.