This is what I found after some experimentation.
In CAPITALS is the function that Behringer has programmed when the BCF is set to MACKIE/CUBASE emulation mode. (See my first post in this thread for all the stuff you need to download) with a description of what it does in Live 5.
F1 - F8: These send MIDI notes so you can assign these yourself with MIDI learn mode.
MUTE: Channel on/off.
RECrdy: Arm track for recording.
VIEW 1..8: These send MIDI notes so you can assign these yourself with MIDI learn mode.
SEL: Select Channel.
FLIP: Flips the Rotary encoders with the faders. (So for example if you are editing filter cutoff you can press FLIP and edit using the fader instead of the rotary which is more responsive).
REVERT: Seems not to do anything in Live.
PAGE+ and PAGE-: Display FX sends and I/O parameters pages.
WRITE: Toggle clip/channel view.
EQ: Previous parameters page when editing instruments/FX (see my first post in this thread on how to do this).
INSTR: Back to arrangement.
VIEW: Toggle faders between the Audio/MIDI and the return channels . If you want to get at the sends in the return channels you have to select the retun with the mouse though.
INSERT: Show instrument and insert devices (see my first post on how to edit).
MASTER: Toggle draw mode (pecil) NOTE: the mouse pointer doesn't change until you move the mouse!
READ: Toggle session/arrange view.
SENDFX: ??? Does something to the faders but nothing useful as far as I can see.
MIXER: Show/hide track/clip view.
SEND: Next page of parameters (see my first post on how to edit).
<BANK & BANK>: Previous/next 8 faders.
<CH & CH>: Moves by 1 fader. Say you were editing faders 9..16 if you press <CH you will then be editing 8-15.
UNDO: Doesn't seem to work in Live.
REDO: No go either.
PREV: Punch out switch.
LOC L: Goto previous locator.
NEXT: Doesn't seem to do anything in Live.
LOC R: Goto next locator.
>>: Fast forward.
ADD: Deselect in arrangement view as far as I can see. (Not very useful).
PUNCH: Punch in switch.
I have made little printed strips of paper for myself to mark all the buttons, but since a lot of the Cubase functions are something completely different in Live I will be redoing them with all the Live functions printed on them.
Will post it here (as soon as I get round to it) for whoever wants to print it out and get busy with scissors and glue.
Until Behringer decides to do a emulation especially for Live this works extremely well! All devices are editable in pages of 8 parameters at a time. If you have more than 8 sends: Again you can get to a new page(s) and edit them. Plus, there are still 16 switches that you can assign yourself for firing clips or scene increment/decrement/lauch.
Hope you find this useful.