I am making a mod that adds a Bauble that enables a Keybinding to fire a rocket in use with an Elytra to avoid having Fireworks in the hot bar.
The item works as expected, but the rocket never stops propelling you forwards. My best guess going on Mojang's code is that it automatically applies a "LifeTime" to the Entity separate from the spawning code. And due to my code not adding it doesn't kill it.
I tried to add NBT to the Rocket, but to no avail. I could really need some help with this.
You can't do any of this. All entities must be spawned on a server, not the client, and inventory manipulations must also be done on the server, not the client. You need to send a packet to the server and do all this on the server.
How would I go about making a packet to send an ItemStack and EntityPlayer to the server? And listen to them. I just read through the Forge Doc about networking and SimpleImpl. Or can I only send Int?
How would I go about making a packet to send an ItemStack and EntityPlayer to the server?
You don't need to send those to the server, it makes no sense.
You need to send just enough information so the server can validate it, find the player, find the itemstack in their inventory and do whatever it is supposed to.