Interesting, so you mean control the PLL logic with an old style channel select knob/diode matrix?
I'll have to look into this.
No. The PLL uses serial communications to set the frequency. You'd need to know the serial commands, which should be available by "sniffing" the comms between the processor and the PLL. Once you have the commands you can then program them into another processor to run the PLL.
Yes, I simplified a lot and there's probably other ways to get the data.