Re: Instrment panel
YES - the airbag diag socket is behind the curved panel - yellow lead.
As for the battery thing - my battery has been disconnected/reconnected a dozen times now - without the airbag light coming on once.
This is the trick - if you remove all power from the car ie. disconnect the battery - BEFORE disturbing the airbag system - providing it's all back together when you reconnect the battery - you'll get away with it. But if you disturb the system with battery power still applied to the airbag ecu - then you are likely to be welcomed back by a permanent airbag warning light! The same applies to all parts of the airbag system - the dash, any of the airbags (steering wheel, passenger, facelift seats) and seatbelt pre-tensioners.
ALWAYS disconnect that battery.