I've seen it too many times when a new player joins (or a low level player joins) and they type !ammo, !goto, or !regen.
I think it would be a good idea to make it so that when timer disabling commands like these are typed into chat, there should be some sort of confirmation i.e.: type it again in chat (after a warning appears). The warning could be simple; "using [ x ] disables the timer for [ x reason ]. Disabling the timer will also result in no awarded points after the completion of the map" would do in my opinion.
This is really simple, but I think it would be easy to implement and could educate new players on how these commands affect them.