Unlikely you're in 1AK, only Emeralds can sit there and I'd expect them to show as occupied if you were there. Give BA a call and they can allocate the seats you want (/allowed!).

Hopefully BA pull out all the stops to make your trip memorable and make up for their previous mistakes. I wouldn't be holding my breath though!

85 mins is tight but perfectly doable - you will indeed to re-clear security at the flight connections security section.