You can make the uneven bricks even by laying a 2' piece of 4 X 4 on top of them and hitting it with a mallet. If some have sunk too low to suit, you could remove them and fill with sand to get the even heigth, then I agree with the sweeping sand into the joints. Keep in mind though, the sand will not stay in place it you are going to sweep it frequently or use a leaf blower on it; that's when you want to add the portland cement to the sand before sweeping it in. When you are satisfied with the bricks and sand/cement, a light fog of water sprayed over the drive will set the cement. Just let the fog fall on it to keep from washing out the sand/cement.