Prince of Eckmühl
I got to thinking about the questions that you posed above. They're insightful ones, indeed. And while I'm certainly not gonna try and respond to your query on behalf of anyone from the development team, I do have considerable interest in how these issues have been handled from the standpoint of board-gaming, which is, after all, the conceptual antecedent to games such as CAW.
So, for the sake of "accuracy in reporting," I dug them all out of the closet, my fleet of operational-level games which focus on carrier battles, Midway x2 (AH), Guadalcanal (AH), Fast Carriers (SPI), Carrier Battles (RSS), Coral Sea (GDW), Flattop (AH) and SOPAC (Avalanche). Then I sifted through the rules seeking clues as to how the designers had sought to address your (and my) desire to have considerations such as you've raised dealt with in an effective manner.
As you will see below, the results were disappointing...
Question: Apparently all ships in a TF are displayed on the combat screen. Do IJN CVs benefit from AAA support from other ships in their TF even though IRL almost all of those ships would be too far away from the CV to actually render that support?
Having scanned the rules of all the games cited from my collection above, I could find few attempts to deal with this issue.
SPI's Fast Carriers makes provision for carriers to turn one hex-side, in place, movement that can affect the results of torpedo a/c attacks. One element of the rule is that any ship within four hexes AND within the 60 degree arc transcribed by the carrier's turn must be displaced one hex AWAY from the carrier. The practical result of this is to scatter the formation, and thereby diminish the ranged-fire available to help defend the carrier. The rule isn't nationality-discreet. This really doesn't strike me as applicable to IJN doctrine of spacing ships so far apart when there were, as yet, no enemies in sight.
Which brings us to the other game that deals with ship-spacing, one that handles the situation somewhat more authentically, right down to which navy did what, and what the differences mean. That game is Carrier Battles by RSS. CB provides for two types of formation, tight (one space between ships), or loose (two or more spaces between ships). These formation types affect gameplay in two ways. Ships in tight formation have a better AA "umbrella," while those in loose formation suffer because of the ranged-fire rules. Conversely, a ship in loose formation can reface to an adjacent hex-side every second turn, whereas a ship in tight formation can only change facing every fourth turn (they had less room to maneuver).
And that's all that my genre-specific, board-gaming research turned up as regards the effects of doctrine, ship-spacing and it's effect on AA. It's worth mentioning that the Japanese were, by mid-1943, tightening up their carrier formations as well. So, if a wargame/simulation is gonna deal with this issue effectively, there would have to be a time/date demarcation as relates to doctrine and the spacing of IJN vessels.
Question: Does Japanese CAP, which more or less functioned without any effective shipboard direction throughout the war perform at reduced effectiveness as a result? Does early war US CAP perform somewhere between "these extremes"?
This one is really tough. I could find hardly hide or hair of any mention of the disparity between the capabilities of the USN and IJN in this regard. The one exception was the not-infrequent application of what could be generically termed as "radar rules." But, in every case, these are some manner of advance-warning mechanism (or outright combat results abstraction) which attempts to account for a U.S. side which is better able to prepare its defense, rather than better able conduct its defense, the latter of which, I believe, is what you're looking for.
Designers of a game like Flattop can reasonably claim that they took the affects of radar and effective fighter direction into account when they created their combat resolution systems, but who knows? Combat in some of these games is so abstracted as to be almost silly, "Task Forces could as well be triremes throwing lawn-darts at one another," to quote an old friend. In the defense of the creators of these titles, they were created twenty to forty years ago. As such, the talent were in no position to benefit from the ongoing historical research into the subject that has done so much to illuminate the topic for you and me.
As for CAW, I'm not completely sure what, if anything, Mr.Wizard has up his sleeve in regard to the issues that you've raised. I simply don't know how deep they've decided to go with some of this stuff. One thing is for sure, the tactical displays look great, and should serve to enhance an important component of any successful computer game, the joy of play, the FUN!
PoE (aka ivanmoe)
Government is the opiate of the masses.