Success! After checking and improving some of the soldering on the header pins connecting the Arduino board to the wave shield, I was able to get the card to read and play audio, although no sound was currently coming out of the audio jack. This would need to be rectified in the coming weeks.
The next step was setting up a map to place all the touch points on. This involved cutting openings into an already printed map to slide the FSRs into. I've only done this for one touch point so far, and the gap itself was fairly crude, but once the touch point was taped in, the slightly messy work was covered.