A disappointing attempt to make a very fast scout

I tried designing a very fast scout for the British in 1921, but the result was very unsatisfactory and disappointing. The issue seems to be the usual. The machinery weight is too great compared to what could actually be achieved. The freeboard is very high, but I will not accept a low seakeeping ability, so this is what was required to achieve something acceptable. I wanted a lower displacement, but the design had inadequate strength, unless the displacement ballooned. This is the Springsharp report:

GB/CL/1927, Great Britain Scout Cruiser laid down 1927 (Engine 1950)

Displacement:
5,119 t light; 5,264 t standard; 5,600 t normal; 5,869 t full load

Dimensions: Length overall / water x beam x draught
469.62 ft / 465.00 ft x 42.00 ft x 16.00 ft (normal load)
143.14 m / 141.73 m x 12.80 m  x 4.88 m

Armament:
     6 - 5.10" / 130 mm guns (3x2 guns), 66.33lbs / 30.08kg shells, 1927 Model
  Quick firing guns in deck mounts with hoists
  on centreline ends, majority forward, 1 raised mount - superfiring
     8 - 2.24" / 57.0 mm guns (4x2 guns), 5.65lbs / 2.56kg shells, 1927 Model
  Anti-aircraft guns in deck mounts with hoists
  on side, all amidships, all raised mounts - superfiring
     8 - 1.57" / 40.0 mm guns in single mounts, 1.95lbs / 0.89kg shells, 1927 Model
  Breech loading guns in deck mounts
  on side, evenly spread, all raised mounts
Weight of broadside 459 lbs / 208 kg
Shells per gun, main battery: 120
8 - 21.0" / 533.4 mm above water torpedoes

Armour:
  - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.00" / 25 mm       -         -
2nd: 1.00" / 25 mm       -         -
3rd: 1.00" / 25 mm       -         -

  - Conning tower: 2.00" / 51 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 114,050 shp / 85,081 Kw = 36.00 kts
Range 4,200nm at 15.00 kts
Bunker at max displacement = 605 tons

Complement:
323 - 420

Cost:
£2.216 million / $8.863 million

Distribution of weights at normal displacement:
Armament: 57 tons, 1.0 %
Armour: 37 tons, 0.7 %
   - Belts: 0 tons, 0.0 %
   - Torpedo bulkhead: 0 tons, 0.0 %
   - Armament: 24 tons, 0.4 %
   - Armour Deck: 0 tons, 0.0 %
   - Conning Tower: 14 tons, 0.2 %
Machinery: 2,728 tons, 48.7 %
Hull, fittings & equipment: 2,296 tons, 41.0 %
Fuel, ammunition & stores: 481 tons, 8.6 %
Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
  2,812 lbs / 1,275 Kg = 42.4 x 5.1 " / 130 mm shells or 0.5 torpedoes
Stability (Unstable if below 1.00): 1.21
Metacentric height 1.9 ft / 0.6 m
Roll period: 12.7 seconds
Steadiness - As gun platform (Average = 50 %): 50 %
  - Recoil effect (Restricted arc if above 1.00): 0.39
Seaboat quality  (Average = 1.00): 1.01

Hull form characteristics:
Hull has rise forward of midbreak
Block coefficient: 0.627
Length to Beam Ratio: 11.07 : 1
'Natural speed' for length: 21.56 kts
Power going to wave formation at top speed: 70 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 5.00 degrees
Stern overhang: 2.00 ft / 0.61 m
Freeboard (% = measuring location as a percentage of overall length):
   - Stem:  30.00 ft / 9.14 m
   - Forecastle (20 %): 26.00 ft / 7.92 m
   - Mid (37 %):  26.00 ft / 7.92 m (18.00 ft / 5.49 m aft of break)
   - Quarterdeck (15 %): 18.00 ft / 5.49 m
   - Stern:  18.00 ft / 5.49 m
   - Average freeboard: 21.28 ft / 6.49 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 165.2 %
 - Above water (accommodation/working, high = better): 124.6 %
Waterplane Area: 14,651 Square feet or 1,361 Square metres
Displacement factor (Displacement / loading): 94 %
Structure weight / hull surface area: 74 lbs/sq ft or 361 Kg/sq metre
Hull strength (Relative):
 - Cross-sectional: 0.86
 - Longitudinal: 3.57
 - Overall: 1.00
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is excellent