And to continue with the discussion of chunks; an inexperienced player that follows the rules can still create quite a problem with his/hers quarry.
Yes they can. However as you yourself have pointed out on several occasions, the server is often very laggy - So we are taking steps to reduce the lag, by looking at some of the most lag inducing areas. Reducing quarry size, limiting it to one per player and stopping the use of water in quarries, is one step - which will hopefully combat a lot of lag and make playing on the server much more enjoyable for all.
If you could write up a tutorial for people on how to set up an efficient quarry, that would be very helpful to some of the people here.
While it may cause some inconvenience by having these new rules, we have to work on making better gameplay for everyone. We feel this is a step towards achieving that end.