Glad to hear you're enjoying Scrapbook MAX!. We actually don't have a line drawing tool in the program, but you can find several kinds of frames in the kits included with the software, and a whole bunch of shapes (cutouts) that you can add to papers and photos. Does that help?
Scrapbook MAX! is a layout tool that lets you combine objects and then resize, rotate, layer on your page. While we don't have a drawing tool, we have several awesome image editing capabilities, like our eraser (allowing you to extract items from photos, or add blurred edges), the ability to add image effects, and of course all of the amazing things you can do with text (writing on a curve, bend, squish, distort, stretch, add patterns, outlines, and fills, etc.).
No explicit tools in Max, but you can create lines and boxes yourself in Max very easily...
All you need is a little plain coloured image. EG: a 5 pixel square .png, .jpg etc
(doesn't have to be 5 pixels... can be 1, can be 10 or 100..)
Try in the construction papers folder in max 2.
Bring it into your project as a paper, press "S" and resize it until you get the line shape that you want, either vertical or horizontal. You can also change its colour in the properties section (double click or right click it, then properties/advanced).