When you trace off the pattern the only lines that will show are the lines between the points chosen. Also the curves selected. So make sure your curves all have points at either end.
Once you have finished drafting your pattern, then you need to create the pattern pieces. To do this, you need to select the Add New Pattern Piece tool:
Exactly. A draft block is there only to create the points and curves. Then you connect the points and curves to create Pattern Pieces. You can create any number of pieces from the same block. For ex: