I'm using the teens 3.6 + audio shield + ili9341 display. They work fine. I wanted to add a blackberry trackball, it requires some pins for input and 4 for leds. I used 24-30 and 35,36 now i'm getting some issued with the display.
Pins 27 and 28 are SCK0 and MOSI0 (however not by default from the pinout on the site). Should i asume that SCK0 and MOSI0 that are used by ILI9341 and the audio shield can't be touched so i can't use those 27 and 28 pins ?

Also could i use the PulePosition library to read data from the blackberry breakout, the signals seem to be hall sensor output (https://www.sparkfun.com/products/retired/13169)