I replaced the BCM in my 2008 CX-9...need a little help

My 2008 CX-9 with SmartKey started acting funny a few weeks ago i.e. all dash lights on, turn signals not working, power locks not working, etc. My research showed that it was probably a bad BCM, which was correct. I bought a replacement on ebay and switched it out. Almost everything is back to normal now. However, my smartkey no longer locks or unlocks the doors. Also, the red "KEY" light stays on all the time and is accompanied by beeping while driving. I can still start the vehicle without a key in the ignition which seems odd to me. So, I'm guessing I need to take it to a dealer to be reprogrammed or there may be a cheaper, easy fix that I can do at home. Does anyone know what the best thing for me to do in this situation? Can I do away with the Smartkey system all together and buy a used antenna with new plain keyfobs? Also, does anyone know of an aftermarket headlight system that would work for me as I don't want to pay $900 to replace one headlight. This CX-9 has been nothing but trouble since 2015. Thanks for any help that can be offered!

Does the BCM need to be reprogrammed for the new VIN using a OBD scanner as part of the replacement process?

no aftermarket headlights out there for your vehicle.

However there is a brand new passenger side headlight on ebay for 525 if what you need is the passenger side