CMOS digital IC operating voltage?

I found one FM Stereo encoder circuit from the internet. I believe it's a working circuit. I choose this circuit because of easily available parts & specifically 38Khz [76kHz here] oscillator...
when i start the hardware design i struck with two doubts...

Q1. They pointed as the 4066 IC is operating at +12v & -12v, but the maximum operating voltage from datasheet is +7.5v & -7.5v.
Q2. 19Khz pilot frequency [square wave] has a low pass filter? It's a single frequency so why we need a low pass filter. is it a wave shaping or something else?

Regards
Udhay