How to disable camera movement with "<" and ">" key?

An alternative would be to copy the default control scripts and modify them slightly. Here's a step-by-step:

1. Play a game in studio so that your character spawns.
2. Copy the CameraScript found under game.Players.Player.PlayerScripts.
3. Stop the game. Paste the script into game.StarterPlayer.StarterPlayerScripts. This will replace the default camera script whenever the player enters the game. Now you can start editing.
4. Go to the module CameraScript.RootCamera. You should see something like this, starting at line 494:

--[[elseif input.KeyCode == Enum.KeyCode.Comma then
				local angle = rotateVectorByAngleAndRound(this:GetCameraLook() * Vector3.new(1,0,1), -eight2Pi * (3/4), eight2Pi)
				if angle ~= 0 then
					this.RotateInput = this.RotateInput + Vector2.new(angle, 0)
					this.LastUserPanCamera = tick()
					this.LastCameraTransform = nil
				end
			elseif input.KeyCode == Enum.KeyCode.Period then
				local angle = rotateVectorByAngleAndRound(this:GetCameraLook() * Vector3.new(1,0,1), eight2Pi * (3/4), eight2Pi)
				if angle ~= 0 then
					this.RotateInput = this.RotateInput + Vector2.new(angle, 0)
					this.LastUserPanCamera = tick()
					this.LastCameraTransform = nil
				end]]

comment these statements out (I did it for you already). This should unbind the , and . keys from controlling your camera!