I for one dont much mind long transit times. I like realism and if in reality it take awile to fly there then so be it.
It just gives me more time to assemble my flight, climb to altitude and then take in the scenery and mentally prepare.
As far as the fuel issue goes, just take less ordinance and add more external fuel. (realism again)
Of course if you have 3 bags of gas hangin on yer Phantom and they are allready empty when you get to the target....
well maybe you gotta use a different aircraft. ("The Mustang cant do what a Spitfire does BUT it does it over Berlin")
I guess my whole point is to not modify a terrain just cuz the flight times may be a little long. I will fly it anyway.
Disclaimer: Im also the type who when not playing SF will take my CS B707 and fly it from NYC to London :D