I'm not entirely sure what you are experiencing is lag.
Lag is an unintentional delay caused by a low internet speed or the server's computer (or your computer) slowing down.
If you change armour in order to gain access to a clickie on another suit of armour, for example, there is a delay to represent the time to take off, or put on, a complex piece of protection. The lighter the armour, by class, the quicker it takes, with robes being the fastest.
This is not lag, this is an in-game delay to model the change over.
Clickies also have timeouts, to pace the speed at which they can be activated. Again this is not lag, instead it is an in-game feature.