Don't panic! I've sussed out the BAS/ESP. Found it in the manual saying the light may be on after disconnecting the battery. Just go full left lock, then full right lock on the steering wheel and the light is back off again as it should be.

Re. airbag, no, UK cars do not have that button in the center console. I've checked both P and D sides and it isn't there. Looks like a US thing.