Help! connecting After Market HU

i just installed a JVC AVX8000 HU in my 2007 tahoe which had a Bose sound system without Nav. I am not sure about the connections that my installer did. First of all he connected the speaker out from the HU which has a built in amplifier 50w X 4 to the speaker wires from the factory harness which are going to the bose amlifier. instead of connecting it with the RCA preouts. Is it ok to conect that way. Secondly, I am not getting any sound from the IR headphones although I connected the pink wire from the RCA harness as posted by GMGEEK. The lights on the IR on top of the rear screen are all illuminated but iam not getting any sound from the headphones. The JVC is a dual zone unit. Another thing i need to ask is that after installing an aftermarket HU is there any use of the factory remote control. I did not get to use the Headphones with the factory unit so I dont know what were the functions that the remote control actually did. I mean does the remote make any picture adjustments to the rear screen also how do i switch off the rear dvd. What about the volume or any other functions. I would appreciate any help that you guys can extend me. Thanks