Chess960: two move ideas no.12

I was playing Mark Weeks in the first trial of the Fischer-Bronstein Non-Random Chess960 Project. We decided on SP384 which includes one of the ten BBQ 'Barbeque Openings' plus their twins. My first move as white was a reflex reaction and I quickly came to dislike the move because it is too quiet for my liking. So to liven up the position, I played the 'Barbecue Gambit'. If you are interested in these two move ideas, you will see the similarity between this gambit and idea no.9.

SP384 Barbecue Gambit: black to play
Trace back the moves and
try to see white's ideas

Enjoy 960

Hint: if ...cxb4 then in no particular order d4/Qd2/Rc1/Ne3/d5/h4.
White plays for activity on the diagonal and kingside,
 hoping to recover the pawn later,
or to gain tempo if black plays
...a5 down the track