Kris,

The luthiers among us will kill me for this, but the braces are just bits of wood stuck on the underside of the top to stop it vibrating too much.

If your guitar sounds dull it's probably because the top isn't vibrating enough. So after you've done all you can with the finish you might want to take a look inside. Don't take too much off and don't take anything off around the sound hole.

As you say there is little to lose and it's a great learning experience.

You don't need to do anthing to the back, compared to the top, it has little to contribute to the tone.

Have fun. Bert.