EagleDNY,
Here's a little more why I think that way (in no order):
FSO is a completely different mindset than MA gameplay. I have to believe dar is more to create a battle than to end one in the MA. Pearl Harbor comparisons are more for scenarios than MA. The MA is kind of like
StrategyLite.

My observation is that 3-4 sector away CVS are sunk more by spies than by being given away from people upping above dar. It happens almost every morning as the 'day shift' enters the MA.
It is still easy to anticipate the direction of incoming bombers after a CV is known to have been spotted. You just look to the logical fields where bombers would up from that have a dar bar. Every CV-based fighter climbs at least twice as fast as bombers and the maximum altitude of any bombers capable of sinking the CV can be estimated. It will take B-26s about 25 miles to climb at least 10,000', depending on fuel load.
It isn't too hard to figure out a CV is near if all you see are carrier-based planes at a base. The object of those planes is to get control of the base (drop vh, ord and sb) before the fleet can get close enough to spawn LVTs.
The object of the defenders is to sink the CV if the base is overwhelmed quickly, so expect bombers...
I'm not in favor of no dar over water either. Attackers can fly a non-direct route under radar and pop up at a location that confuses defenders about the location of the CV. I do it all the time with my squad and we aren't the smartest guys in the world, so I suspect plenty of others do also. These things are all part of the game, don't you think?
I not convinced that 1944 radar in the main arena spanning 6+ years of technology is something needed. Compromises are made for the sake of gameplay (our GPS maps, aircraft icons and distance, no mixture, no blower limits/controls, no cowl flaps, no overheating, no gun jamming or mechanical or electrical failure, no engine start procedure). Not having these does not detract from gameplay, they enhance the MA for the sake of gaming vs. real-world simulation in an environment that is pretty close to anarchy, not under a structured command system with shared goals.
I don't think more information is needed to enjoy the game. I think more unknowns and surprises are good for gameplay.