I wouldn't mind that on fighters, but definitely think medium bombers have a role in this game.
I brought up the idea of perking the 4-engine bombers probably a year ago and after much debate was laughed at.
I'm glad to see folks have given it time to percolate.
Regarding the lancs: They are easiest to attack, perhaps, but unless you get a cockpit kill, they are the most buggiest with damage modeling (damage disappears, components way too strong, etc). If they are ever remodeled to the quality of the B-17/B-24 and the damage model is revisited during this process, then I agree they will be the most vulnerable. As they stand now they're the hardest to catch and kill because it takes more rounds than on the others.
Oh, and 2x over the past week I've been directly below a lanc after making a pass and both the nose and tail guns have shot directly below the plane and hit me many times (often disabling my oil or some vital component).
We're talking directly below the plane's bomb bays here, 500d and diving away perhaps, and getting nailed. No other cons in the sector.
The plane is so buggy it's hardly defenseless (I say bug, not the c-word)