See a lot more LA7s around I would think.
Yes, that would likely be one effect.
The problem with the 2X fuel burn multiplier is that while bases are closer to targets than they really were, 30,000ft is still 30,000ft away. It makes climbing twice as fuel expensive as it was for a given altitude. For example, a Spitfire Mk XIV, a high altitude fighter, has very little loiter time once it has climbed to 27,000ft and flown to a target area. Just the climb completely consumes its drop tank.
163s would be able to go 8 grids
Me163's are hard coded into the game and the fuel burn multiplier does not affect them. Test it offline.