As far as buffs outrunning fighters: If the fighter is level with the buff at those altitudes, no he won't be able to outrun him. Most times that a fighter is lower than me, I can outrun him but there has been an instance or two that they played it smart and caught me anyway.
I don't want a B-52 in here, just the ability to fly at 30 to 35k. Now some of you, Cave for instance, like to shoot 'em out with fighters. That's cool. More power to ya. I am not that good at it so I prefer to not engage if possible. Do I loose some excitement because of this? Some, not too much though, hate taking the time to get a buff to target and not be able to hit it.
When the games changes to the point that single buff sorties are not as common, i.e. more guys who want to fly buffs are on line at the same time, more people are willing to fly as gunner (and be able to hit what they shoot at), then the need for such high altitude flights won't be necessary. A good bomber element consisting of 3 to 4 bombers would be difficult to shoot down by single attackers. It would take a concentrated effort by several fighters as was recently demonstrated by the Flying Pigs. They managed to decimate a group of 4 or 5 bombers flying in formation without a loss to their own if memory serves me.
Another thing that will change will be the introduction of the B-26. A much faster bomber and one that a lot of us buff drivers will be willing to fly lower.
As it stands right now it is too easy for a single pass kill of a buff with one fighter assuming he dives in on the buff from a higher alt and a lot of speed.
MarkAT