How can i extend Bluetooth range at maximum?
As far as I can tell, the nRF51822 uses a common port for transmit and receive: -



How can you get inside the chip to amplify the TX transmission when it is being transmitted and then switch back to RX when intending to receive?

EDIT section: -

It seems that NORDIC say this about the VDD_PA pin: -


  Logic for tuning the PA on/off can be used via pin "VDD_PA", which
  goes high around 80 us before a TX-transmission occurs and goes low
  again when it's finished.


Basically this means that to add a PA (more power output) you have to design an external duplexer switch so that you can control signals into and out of ANT1 and ANT2.