No new suggestions, just reiteration of a few good ones:
Fuel - I really like the idea of limited fuel - it means you can't afford slashing attacks and have to stay in the main fight. It also means you have to be careful about your maneouvering and know when to disengage and run for home. Perhaps disabling the fuel feature on the demo as there are no cap ships to refuel from would work, but other missions should be realistic. 1.5 hours' worth of fuel at full power is hopelessly over optimistic - modern fast jet aeroplanes deplete their entire fuel load after 10-15 minutes with afterburner engaged!
Views - I like the spring centred wide angle view that reacts to inertia. I'd also like to remind the team of someone's previous thread about supporting VR goggles or systems like the Track IR.
Hand of God - its critical to include this mission for the historical campaign. I understand your concerns about the tunnel being an insufficient challenge, but it was very confined, there were a lot of obstacles in there, some of which were moving, and Lee had to fly it very fast (for the game, you could reasonably place Centurions in the tunnel who shoot at you - smaller weapons, but you'd have to fly fast to avoid multiple hits and this increases the challenge). Furthermore, to make the tunnel harder, its path could be randomly created by the computer to simulate the lack of intel and planning on Lee's flight.