1 .Download the eagle files from the sparkfun.
2. After you take a look in the board file, at the wirings, check them with the multimeter your Arduino.
3. If something doesn't seem to be there, resolder carefully, and if it doesn't still work, rewire the Arduino wirings with some thin wire to the closest part.
4. Yes. GND and CTS are both the ground.
5. Why did you scrubbed with a fiberglass pencil?