Hi Jamie ( @jmq1 ),
Well done for booking tickets – it’s a great experience!
I went last year and drove there so can’t help with any flight experience, but maybe I can help with your timings. The pit lane is open on Thursday to everyone with 3-day tickets, it was a nice opportunity to familiarise ourselves with the surroundings and we got up close to all the garages, and saw Vettel and Hamilton. I would recommend getting there early as the queue is quite big.
In terms of returning home on Sunday, I’d say the flight departing at 20:50 would give you plenty of time. You should easily have left the circuit by 4pm, so you should be fine.