Seems to be impossible to have a thread about US cruisers here anymore.
Part of making a realistic PD/AU design is introducing flaws (like the many "mistakes" you've called out re: prewar USN practice). To me these make the designs more believable.
An interesting personal design USN cruiser to me would follow the basic design practices of the period (including the flaws) but introducing a new "shape" to the ship itself. I'm not very good at this myself as I tend to only draw real designs as I don't consider myself a ship designer but rather a ship drawer. But that's just me!
It would be interesting to show this cruiser in several different "year" iterations. If it were up to me I'd draw these:
1. 1929, as built.
2. 1935: a few light AA guns added, painted in pre-war light grey with large hull numbers.
3. December 7th, 1941: more light AA, Measure 1 dark grey scheme with light grey above the funnel tops, CXAM radar above the foremast. Bathtub of .50-cals above the mainmast.
4. Maybe a drawing of a sister ship stationed with the Asiatic Fleet painted in Cavite Blue with a slightly-similar fit?
5. A drawing of that same sister ship as sunk at Sunda Strait along with HMAS Perth and USS Houston, weathered Cavite Blue and maybe a Measure 5 false bow wave?
6. CA-1929's original unit in 1942, with a lot more light AA (mostly 1.1" quads and .50-cals) and a single SG surface search above the pilot house. Likely painted in Measure 21 (overall 5-N Navy Blue).
7. CA-1929 original unit in 1943, with 40mm Bofors quads replacing the 1.1" and 20mm Oerlikons starting to replace the .50cals. A revamped foremast with an SK air search radar and the SG surface search set relocated to the mainmast. Probably painted in one of the cruiser Measure 32 schemes.
8. CA-1929 in 1944, with the standard mid-to-late-war radar fit of SK/SG on the foremast and SG on the mainmast. Maybe a few Mk.57 radar-assisted directors above the pilot house. The basic SPT-1 ECM suite on the yards, with a few of the early corner reflector TDY jammers on the front of the foremast and aft of the mainmast. Probably painted in Measure 22 (graded system) as the ship becomes basically a shore bombardment vessel and carrier escort.
9. CA-1929 in 1945, with the SK upgraded to an SK-2, and maybe an enlarged mainmast with an SP or SM height finder. Late-war TDY trainable jammer assembly on the aft funnel, with associated monitoring antennas ahead of the pilothouse. TDY-1A S-band jammers in radomes along the deck edge and a receiving antenna on the mainmast. Even more light AA. Maybe it's painted in the later Measure 22 graded system based on the grey instead of blue paint tint.
Kind of makes me want to design a few cruisers!