The location of the heading box, it is configured by the app with no way to move the location at this time.
The compass heading issues. The built in compass is very subject to interference, do not have the device on anything electrical, like on top of a laptop or against your phone for example. Plus they just drift
The app has a few options for dealing with the built in compass.
First, compatibility mode for this tablet. If you are running android 4.0 Jelly Bean, use the compatibility modes. If you are running 4.1.2 Jelly Bean, DO not use the compatibility mode, Samsung fixed their error.
Next in the compass menu, you can adjust your degrees + or - on how the app displays your heading based on your device.
Below that you can adjust the sensitivity of the of the compass, how quick it is to respond to changes.
Outside of these options, you are stuck with the performance of the hardware.
Let me know if you are not able to resolve the issues.