As for concept of fast bomber, while it backfired in day ops, it was very workable for night ops. The night fighters were inherently heavier draggier than day fighters ( usually 2-3 seaters, antennae sets for Luftwaffe types, heavy armament), so most of them resembled performed more akin to bombers, than common fighters. Too bad Americans didn't built (X)B-38s (with turrets replaced by single HMGs, no waist guns) for RAF Bomber command.