My design for a Ger/CB/1918 with 8-17in guns

I thought that I might be able to design a German battlecruiser, along the lines of what was actually planned, but with 8-17in guns, a 12in belt, and a 29 knot speed. This would be a "Hood Killer", although the German ship is slower. This is my Springsharp report:

Ger/CB/1918, Germany Battlecruiser laid down 1918 (Engine 1921)

Displacement:
 40,822 t light; 42,784 t standard; 44,800 t normal; 46,413 t full load

Dimensions: Length overall / water x beam x draught
 803.81 ft / 803.81 ft x 101.71 ft x 31.17 ft (normal load)
 245.00 m / 245.00 m x 31.00 m  x 9.50 m

Armament:
      8 - 16.93" / 430 mm guns (4x2 guns), 2,425.91lbs / 1,100.37kg shells, 1918 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      14 - 5.91" / 150 mm guns in single mounts, 102.98lbs / 46.71kg shells, 1918 Model
   Quick firing guns in casemate mounts 
   on side, all amidships
      8 - 3.46" / 88.0 mm guns in single mounts, 20.79lbs / 9.43kg shells, 1918 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, all amidships
 Weight of broadside 21,015 lbs / 9,532 kg
 Shells per gun, main battery: 90
 5 - 23.6" / 600 mm submerged torpedo tubes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 12.2" / 310 mm 557.74 ft / 170.00 m 9.84 ft / 3.00 m
 Ends: 5.91" / 150 mm 213.25 ft / 65.00 m 9.84 ft / 3.00 m
   32.81 ft / 10.00 m Unarmoured ends
 Upper: 9.84" / 250 mm 557.74 ft / 170.00 m 9.84 ft / 3.00 m
   Main Belt covers 107 % of normal length

   - Torpedo Bulkhead:
  2.36" / 60 mm 557.74 ft / 170.00 m 31.17 ft / 9.50 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 12.2" / 310 mm 7.09" / 180 mm  12.2" / 310 mm
 2nd: 5.91" / 150 mm 3.15" / 80 mm  3.15" / 80 mm

   - Armour deck: 3.15" / 80 mm, Conning tower: 12.20" / 310 mm

Machinery:
 Coal fired boilers, steam turbines, 
 Geared drive, 4 shafts, 138,782 shp / 103,531 Kw = 29.00 kts
 Range 4,500nm at 14.00 kts
 Bunker at max displacement = 3,630 tons (100% coal)

Complement:
 1,539 - 2,001

Cost:
 £8.743 million / $34.971 million

Distribution of weights at normal displacement:
 Armament: 2,627 tons, 5.9 %
 Armour: 14,866 tons, 33.2 %
    - Belts: 5,581 tons, 12.5 %
    - Torpedo bulkhead: 1,519 tons, 3.4 %
    - Armament: 3,900 tons, 8.7 %
    - Armour Deck: 3,534 tons, 7.9 %
    - Conning Tower: 332 tons, 0.7 %
 Machinery: 5,257 tons, 11.7 %
 Hull, fittings & equipment: 18,073 tons, 40.3 %
 Fuel, ammunition & stores: 3,978 tons, 8.9 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   52,406 lbs / 23,771 Kg = 21.6 x 16.9 " / 430 mm shells or 7.2 torpedoes
 Stability (Unstable if below 1.00): 1.05
 Metacentric height 5.6 ft / 1.7 m
 Roll period: 18.0 seconds
 Steadiness - As gun platform (Average = 50 %): 60 %
   - Recoil effect (Restricted arc if above 1.00): 0.96
 Seaboat quality  (Average = 1.00): 1.20

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.615
 Length to Beam Ratio: 7.90 : 1
 'Natural speed' for length: 28.35 kts
 Power going to wave formation at top speed: 50 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 0.00 degrees
 Stern overhang: -6.56 ft / -2.00 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  36.09 ft / 11.00 m
    - Forecastle (20 %): 29.53 ft / 9.00 m
    - Mid (50 %):  29.53 ft / 9.00 m (19.69 ft / 6.00 m aft of break)
    - Quarterdeck (15 %): 19.69 ft / 6.00 m
    - Stern:  19.69 ft / 6.00 m
    - Average freeboard: 25.13 ft / 7.66 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 105.1 %
  - Above water (accommodation/working, high = better): 181.9 %
 Waterplane Area: 60,655 Square feet or 5,635 Square metres
 Displacement factor (Displacement / loading): 97 %
 Structure weight / hull surface area: 209 lbs/sq ft or 1,019 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.98
  - Longitudinal: 1.20
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is adequate
 Room for accommodation and workspaces is excellent