@  insanepinecone: Making 1/8th-width lines is easy to pull off.  All you have to do is put a brick in one box, put another brick (same or different) seven spaces away (or a gap of six between them), highlight them all, and then press Shift+G to combine them into its own unique brick.  Once created, move your mouse to the newly created brick and hold Shift upon cliking it; the standard bricks that compose the newer one will be magnified.  Your pointer will change into an eraser, and you can then click each portion to erase what's not needed.

I've got an image attached to show how this can be performed.  Unfortunately, the eraser icon is absent despite trying two full-screen captions (my computer's acting belligerent in that regard).  Hoefully, the image should be of enough use.

@ insanepinecone:  When you hold Shift as you click on a custom brick, a gray box will show up with the component pricks and the mouse cursor should change into an eraser.  While the cursor is shaped like the eraser, you'll be able to click on each of the unwanted bricks within the gray box until you only have one left.  For example, in image I posted above, if I wanted a 1/8th-width line that goes along the left side of the brick, I'd click the eraser pointer on the six circles in the center and the square on the right to clear them out so that only the square on the left remains.

Does that help clarify things?

No problem!