Well now - no luck in getting this player distributed yet so I just connected it local for the purpose of doing this driver.
c4i driver file for pre 2.6:
https://www.dropbox.com/s/99vm6y1q9mwb5im/dvd_Samsung_UBD-K8500.c4i?dl=0
c4z driver file, will show custom icon in 2.8.1 and up (should work on earlier versions down to 2.6)
https://www.dropbox.com/s/4iog1cdwja2e2ca/dvd_Samsung_UBD-K8500.c4z?dl=0
All 'different name' buttons are available for programming or mapping to the color buttons/custom 1-3 buttons.
I added both ABCD and their respective colors to the driver as codes,for redundancy.
'eject' is mapped to channel up
'pulldown' (info/123 hold) menu to channel down - this one's a bit wonky though
'home' is mapped to page up
'tools' is mapped to page down
'netflix' is mapped to record
'return' has been mapped to both prev and cancel
'title/pop-up' is menu
'disc menu' is guide
The downloads/driver section of the forums does not yet allow c4z files (already requested) - but once it does I'll upload them there as well.