What I can say is that you have a short-circuit on the half speed crystal, and dont know if also has one on the pitch bend (dont know the pinout)
I tried to do something similar and my test gameboy is dead because of that xD
I tried to have a 3 positions switch: 0.5x 1x 2x
for that I used a 3 positions switch, one that have 8 legs, but if you only have ON/OFF switch, that I suppose that have 3 legs you can do...
SWITCH1
Leg 1----------------------->Pin1 Crystal 1 Pin 2<----+
Board Pin1-------------->Leg 2 Leg 1------>Pin1 Crystal 2 Pin 2<---+
Leg 3-------->Leg 2 |
Leg 3------>Pin1 Crystal 3 Pin 2<---+
SWITCH2 |
Board Pin2------------------------------------------------------------------------------------+
I dont know the pinout for Pitch Bent, but I think you can change Crystal 3 for that
Hope that my ASCII art helps you