Hi,
I have a feeling that I am almost there having the wonderful setup of using the remote control of my Fire TV Stick with Rasplex. I have enabled Bluetooth, the system can find the Fire TV Stick, but I cannot get it to pair. I know there is some communication going on, because when I simply try to pair, it says it can’t find it. When I hold the home-button on the remote for 5-10 seconds and select “Pair”, it gives me a dialog where I have to enter a code. I have tried several combinations including 0000 and 1234 (still while holding the home-button), but every time I get the message “Received no reply”.
It feels like I’m almost there… I just need that final step… 
Thanks!