OK 2 parter

1) I have a copy of TBC but no more disks for original wow. I am wantin to duel box 4 or 5 accounts here. Can I just copy the wow directory into 4 new versions ie

D./worldofwarcraft1

D./worldofwarcraft2

D./worldofwarcraft3

D./worldofwarcraft4

D./worldofwarcraft5

Or do i need to go out and physically buy 4 more copies of orginal wow + TBC.

Finally is the set up of 4 elemental +1 resto shammy the way to go?