You can't open the editor with a command. There is a dll that allows you to make commands for ctrl & alt commands. I think it is altkey.dll or hotkey.dll.
Help file is "/help search string".
I havent used dcc. Does each dcc open a seperate window? Also, if you keep track of your dcc's you will have your own list. Make a custom identifier if you need.
To disconnect from a server use /disconnect. You will need to make sure the correct connection is active with /scid or /scon.