We need the levitation and shulker added in to learn to mod as well as the ability for drones to drop items and splash potions and snowballs to be added to enteties
Also make eggs an entity as well as ender pearls and eyes of ender there all entities you can summon them using the summon command and add a way to enchant items.
You should be able to use snowballs and eggs (I think eggs), as projectiles on our minecraft server. For an example of how to use snowballs, check out the Gotta Catch Em badges.
The badge doesn't spawn snowballs though, which is what I'm after.