This really hits the question of do you have hindsight and do you want to deter or win a war?
You are OP-20G, (the NGS) not the General Board. You just came out of WW I and you have to figure out the navy problem for the next 20 years.
What do you know from WW 1?
Mines, torpedoes, shells, bombs (dud rates high), fire control issues, failures of naval reconnaissance, failures of naval communications, failures of fleet command and control, damage control procedures, COMMERCE WARFARE (subs), and MANPOWER issues.
This is where the British, Germans and Americans fell down.
Battleships don't rank very high on that issues list. Neither does planning the naval campaign (ORANGE), but that will be what physicists call an emergent solution as one addresses with foresight, not hindsight, the perceived known problems.
1. Mines, torpedoes and shells. Addressed, but not with enough peacetime effort. That peacetime failure had to be fixed 1942-1943 with 3x the money that would have been spent in proof and exercise and Murphy knows how many lives to make the developmental prototypes into working proofs. Live war-shots in peacetime mean less hassle in war.
2. Fire control issues. No matter how one slices and excuses the USN's poor shooting in WWI, there is no doubt that the RN was better than the USN and the KM better than the RN. This will be fixed.
3. Despite the belief that I have that the Battle of Jutland was an aberration and a misread of Colbert and MAHAN, the three issues of naval recon, comms, and fleet control will be addressed. The radios will work, USN recon doctrine by air and sea will be first rate, (in theory) but fleet control (staffing) will be a major problem. There are 2 fixes. Fleet-exes and krieg-spiel (German wargame methodology to test battle drill concepts), but the one thing the USN does not do is weed out the !@# !@#$ Brownings, Mitschers, and Englishes in the gaming process like the Germans between the wars did and Marshal for the Army does. King will get around to it by 1944, but it costs lives, a lot of lives
4. To go with 3 is "battle drill". It is one thing at the NWC to train your future tacticians with Papierkarte Kriegsführung (War play on paper). It is another thing to be in the middle of the southern Philippine Islands making mock destroyer attacks on op-for "Team Orange" in the rough weather with live stupid human beings, faulty machines, futzed communications and at NIGHT. The USN will get this training with a live op-for in 1942 in the Solomon Islands. It will not go well. Goof up in peace and learn, kill the enemy easier in war.
5. Damage control procedures. RTL actually good, because the HSF fleet reports post Jutland were eagerly studied and DC lessons learned applied, but op-analysis of the Lexington and Saratoga peacetime fires and incidents should have rung alarm bells and made aviation induced damage control incidents a high priority. Lexington, Yorktown and WASP were preventable.
6. Commerce Warfare. This is what WW I actually teaches, so destroyer and cruiser classes for convoy and fleet defense against Mister Sub is the overriding ship-building action indicated and Mister Sub for offensive naval warfare, early and often, based on what the USNGS knew in 1920.
I think you end up with 4 different answers depending on the above,
Hindsight - Win, SS, mines and B17s with guided bombs (not Rikkos we could do better
)
Hindsight - Deter, 100M$ cash in an envelope to France to stand up to Germany
None hindsight - Win, balanced fleet (as we don't know what will actually work?)
None Hindsight - Deter, battleships heavy as that's what will actually make IJN think far more than better secret stuff or RTC colleges in US...... (I was going for this one with my 6+6 BB fleet)
I think building 6 NCs in 37-40 and then a second batch of 6 Iowas 39-ealry 42 would be a significant deterrent to IJN more so that any light/reserve force/internal development as it would make a surface BB action wildly unbalanced with Y&M only completing in 41/42.
I've answered (1).
Cruiser/frigate/destroyer/destroyer escort choices.
As to your fleet,
A- like but its new so will need a longer redesign than simply building an existing class, I would also go 4x2 DP to make totally sure v any DD in a surface fight.
B-Yes but again
Brand new and will face the problem of why v the Frigate I would only build one type (and people will want a 6" ship as well as 5/38" will be to weak in daytime surface fire)
a. ^ 15.2 cm/53s are too specialized for the general threat, but if you want an improved Omaha (5 x 2 15.3 cm/53 4 x 2 12.7/38 and 2 x 5 TT for fleet escort, convoy protection and cruiser destroyer flags, I'm not adverse. 10,000 tonnes covers a LOT of sins if you don't overload and you remind yourself it is supposed to control a fight more than fight the fight. Leave that to your frigates and destroyers. Frigates exploit a loophole in the naval treaties. USCG cutters (DEs) same.
b. Answered under B.
C- 1,500 is DD not DE territory in 37, since they are not limited by 2LNT I would simply build a quick set of the last 1500t design why waste time?
Because with all 3 classes you have to factor in PACIFIC ocean endurance factors. Steel is cheap, big hull, big fuel bunkers and Fletcher is killing IJN flattops instead of constantly topping off his destroyer's fuel bunkers. Also with USN DP guns EVERYWHERE, you are not Tanaka, Raizo raging against McCain's Cactus Air Force as he bombs the Murphy out of your Tokyo Express day and night. You will be Moosebruger able to run under your air cover in daylight and not too afraid of IJN Rikkos because you have the AAA to beat them off and the AshW capability to sink the Express day or night.
Finally with reference to Rikkos, you need to be able to Bismarck Sea from Day 1 and you will not have BAT yet. So, you train Dambusters style and you bomb skip against target sleds. That means B1B (R)s and a lot of practice with retarded fall and bouncing Betty bombs.
D- But this is the main public deterrence against IJN I would want 6 to over match any IJN building program, ie 2 Y&M or more likely in USN mind 4 35,000t ships.
The USNGS already knows "Through Ticket to Manila with a Jutland style coda":, is nonsense. It's Spanish American War with a sub campaign and aerial bombing thrown in for G and Gs, so why build for the wrong thing? .
E- Destabilizing and only works if you intend to break treaties and might get IJN to work on ASW don't want that...... (and they are quick to build so just a few and solving torp problem would be sufficient with hindsight)
Not just fighting Japan.