You don’t really need to be worried about 30 player firing a gun at once. So long as you are not firing a RemoteEvent every frame you should be fine.
Also, it doesn’t really matter where you put RemoteEvents so long as they are put somewhere Replicated to the player e.g. ReplicatedStorage, Player, Character, Tool, workspace.
Preferably ReplicatedStorage as it keeps things tidy and centralized.