"Adding a special fuel burn multiplier would only really change the range, not the dynamic (you'd still have people diving their B17's to gain speed)."
Not so. Think of it this way. It's nearly impossible to get a bomber off the ground with 100% gas. You either get bombload OR gas, not both. By FORCING times when you need more gas in a bomber, people will either slog around hugging the ground trying not to hit trees, never getting above 3k and being sluggish and slow the whole time, or they will take less gas and CRUISE, which means they fly slower. Which means they are realistically catchable as they were in real life.
Given the choice of 100% gas in a B17 and 6x1k bombs, and 50% gas in a b17 and 6x 1k bombs, but using reduced manifold to cruise, which would you pick? Any bomber who has EVER tried to do anything with more than 25% gas knows the difference and they will start slowing down.
The newbies won't. They'll FFT it til they run out then glide into the ground. So it's a win-win situation!
EDIT: Not to mention those 32k HQ raid mission would go bye-bye. Climb performance is VERY much affected by the weight of the gas onboard, so they'd never get that high. Again, more realistic.