A) That would mean any fireball fired into a small hallway with no cover should not allow any saves

(Be careful about how "realistic" one gets, as D&D Magic is a far, FAR greater violator of common sense. Don't even get me started on how 3.5E dwarves & orcs shoot lasers out of their eyes.)
B) 2 handed weapons do occupy far more killing space in a given area - even in a "narrow" tunnel - which is probably 5 feet wide at a minimum anyway.

(if it is less, then you are taking a penalty to attacks anyway, as you are squeezing if you are medium sized)
C) Reading through 4E; you can attack through a portcullis, just a penalty to attack / bonus to AC.