I'll see if I can answer your questions:
(1). The torsion bar is the actual physical spring ("spring") in your suspension, much like that of coils or leaf springs. They basically twist and untwist when the suspension expands and contracts(ie go over a bump, corner, etc, etc).
(2). Torsion bar suspension gives a lot of control and that's why it is used. If you raise the height of the suspension, you will need to realign the front end for diferences in camber.
(3). Not sure I understand the question.
Thanks,