I have looked at the Touch pHAT and according to the pinout and Magpi Issue 58, the Touch pHAT only uses two pins and according to the pinout (https://pinout.xyz/pinout/touch_phat) these are bcm2 and bcm3. Does this mean I can just solder on those two pins to the touch phat and then use all 38 other pins?
Sure! As long as you also connect the power and ground pins it uses.
Even if you solder the pins to the pHat, you can still pull signals straight from the top of them through the board (as long as they aren’t using any fancy voltage buffers, see: Explorer pHat Impedance Mismatching).
So soldering on the top 6 pins of the pinout should do the job then. Thanks RaspberryPicardBox.
No problem! :) If you need any more assistance just ask.