1- In the deathly Hallows, Remus Lupins code name in Potterwatch was Romulus, Remus and Romulus are brothers in an story from Ancient Roman times.
3-(Hidden Easter egg) The first thing Snape asks Harry was "Potter! What would I get if I added powerded root of asphodel to an infusion of wormwood?"
According to the Victorian Flower Language asphodel is a type of lily meaning "My regrets follow you to the grave." and wormwood means "absence" and also typically symbolises bitter sorrow. If you combined them together it makes "I bitterly regret Lily's death."