Seems weird that sand in a compacting drawer will make sandstone, a 2x2 pattern, but smooth stone wont do bricks, also a 2x2 pattern.

Also I don't know if this goes with what compating draws can do, but if stone slabs would turn into chiseled stone bricks, its a 1x2 pattern but it would be a cool addition with chiseled stone being craftable in 1.8.

I think this is a great idea, I would love to see more items added to this.

IIRC, barring stuff like clay, the way SD generates it's compacting drawer recipes is by searching for "two-way" recipes.

You can create your own compacting recipes to the config file.
There is an example there for clay and clay ball.