Hi MrOmNom, thank you for your cooperation!
I have got only one more question, this is the last one; you mentioned that it is not easy for WE to perform a large operation, such like to mirror 200x200 blocks and place it where you would like. What are the main factors that make it difficult? Is it because the operation makes the server laggy?
I don't know how WE handles the calculations, but I'm guessing that doing anything bigger than a 15,000 block edit is laggy because of the sheer amounts of blocks being edited.
The other things that makes it hard is the process.
a) Select (carefully) the region using //pos1 and //pos2
remember exactly where you did //copy
c) depending on what you're doing, use //rotate or //flip
d) carefully pinpoint the exact coordinate you need to //paste to
The main problem is that when you're making the actual edits to your clipboard, you have no visual aid to help picture what you're doing. THe onyl solution is trial and error up in the sky, and then pasting it in once you know what position is right. MCedit actually has a visual aid, where it projects the clipboard so you can see what you're placing, but other than that....