I know this server is highly vanilla, and I love it, but a cool harmless mod that I’ve enjoyed in the past is the chance for player heads to drop when someone dies (much like the wither skulls). These are not only really awesome decoration blocks for someone’s house, but they are also good trophies when someone wins a PvP bout. They’re also useful to put at the entrances of your home as a way to show people it belongs to you rather than have a sign. Furthermore, if you have a town of multiple people, it’s a cool way to set up a “citizen wall” with the heads so people know who lives here.
As i said, I know Arcane prides itself in being a largely vanilla server, but this is such a small and harmless mod (with really cool benefits) that I think it would be a great addition.