Are you using 1.7.10 or 1.8? This is a known issue for 1.8, since I cant add the armor until Forge is released (I'll fix the crash by removing the recipes temporarily). If you are using 1.7.10, post your crash log. Thanks for the feedback!
You need a multi block structure (like a bed/double plant). Make one block render and have the other be a placeholder. When the player breaks a block, set the other one to air.
This is in the block class, you need to override renderAsNormalBlock to return false.
Post a screenshot of your file hierarchy. Are you sure the texture is in the correct path?
GetDescriptionPacket is what packet gets sent when the tile entity needs to update data (I know it gets sent on world load, I'm not sure when else). onDataPacket is what happens when the packet gets received.
In essence, machine guns would be a rapid-fire snowball, snipers would be a fast, precise snowball, and shotguns would be several snowballs at once. For more advanced, better guns, you should use raycasting to detect headshots and cool renderers.
Just put this where you create your other blocks:
public static BlockYourFluid yourFluid = new BlockYourFluid(liquidElerium, Material.water);
and change ModBlocks.init() to this:
GameRegistry.registerBlock(sbrick, "sbrick");
GameRegistry.registerBlock(icePulse, "icePulse");
GameRegistry.registerBlock(orichalcumOre, "orichalcumOre");
FluidRegistry.registerFluid(liquidElerium);
GameRegistry.registerBlock(yourFluid, "some_name")