You have to add it manually via Add Item. You will have to specify the length and any miters when you choose the molding. Once it is loaded in the workspace, you will have to place it manually.
Sure...click the Add Item icon (the same one you use to load a cabinet). On the dialog that is displayed, click the moldings radio button then select the vendor (most likely Conestoga) and the molding. At the bottom of the dialog you will enter the length and miter angles for each end.
To get the proper length, check the front molding before loading the back molding.
Yep! Anything (almost) that you want to add and manipulate manually gets added this way.
Doors, drawer fronts, drawer boxes, moldings, display boards, display panels. display cubes, display objects and certain hardware can all be added and manipulated in this manner.