The Ger/BB/1905 flush deck alternative design

I have this design study and sketch for a flush-decked German battleship that looks more like a 1916 ship than a 1905 ship. The photograph of one if these ships is a pretty accurate depiction. This is what the original specification looked like:

Ger/BB/1905    Ships "A", "B", and "C" to be laid down in 1905
20,000 tons   490ft
19 knots
21,500 tons normal
27,900 SHP normal
33,500 SHP max
Dimensions: 490ft x 90ft x 29.9ft max, 27.6ft light
Hull depth=54ft
12in belt, 4in+3in decks
turrets 8in top, 8in face, 6in sides and rear
Barbettes 12in
Guns: 8-12in/45  12-6in 45
Weights:
  6920 tons Hull
   930 tons Machinery
   720 tons Aux Machinery
  1216 tons Armament
  8614 tons Protection
  1600 tons Misc

This is my Springsharp report:

Ger/BB/1905 Flush Deck, Germany Battleship laid down 1905 (Engine 1921)

Displacement:
 16,831 t light; 17,661 t standard; 19,535 t normal; 21,034 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
 (490.00 ft / 490.00 ft) x 90.00 ft x (28.50 / 30.21 ft)
 (149.35 m / 149.35 m) x 27.43 m  x (8.69 / 9.21 m)

Armament:
      8 - 12.00" / 305 mm 45.0 cal guns - 850.00lbs / 385.55kg shells, 90 per gun
   Breech loading guns in turret on barbette mounts, 1905 Model
   4 x Twin mounts on centreline ends, evenly spread
  2 raised mounts - superfiring
      12 - 6.00" / 152 mm 45.0 cal guns - 100.00lbs / 45.36kg shells, 150 per gun
   Quick firing guns in casemate mounts, 1905 Model
   12 x Twin mounts on sides, forward deck aft
      Weight of broadside 8,000 lbs / 3,629 kg

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 12.0" / 305 mm 300.00 ft / 91.44 m 17.00 ft / 5.18 m
 Ends: Unarmoured
   Main Belt covers 94 % of normal length

   - Torpedo Bulkhead:
  2.00" / 51 mm 300.00 ft / 91.44 m 28.50 ft / 8.69 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 8.00" / 203 mm 6.00" / 152 mm  12.0" / 305 mm
 2nd: 6.00" / 152 mm 6.00" / 152 mm  6.00" / 152 mm

   - Armoured deck - multiple decks: 4.00" / 102 mm For and Aft decks
 Forecastle: 4.00" / 102 mm  Quarter deck: 4.00" / 102 mm

   - Conning towers: Forward 12.00" / 305 mm,  Aft 0.00" / 0 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Direct drive, 4 shafts, 28,177 shp / 21,020 Kw = 21.00 kts
 Range 8,800nm at 15.00 kts
 Bunker at max displacement = 3,373 tons

Complement:
 826 - 1,074

Cost:
 £1.437 million / $5.749 million

Distribution of weights at normal displacement:
 Armament: 1,424 tons, 7.3 %
 Armour: 7,942 tons, 40.7 %
    - Belts: 2,773 tons, 14.2 %
    - Torpedo bulkhead: 633 tons, 3.2 %
    - Armament: 2,066 tons, 10.6 %
    - Armour Deck: 2,283 tons, 11.7 %
    - Conning Tower: 188 tons, 1.0 %
 Machinery: 970 tons, 5.0 %
 Hull, fittings & equipment: 6,494 tons, 33.2 %
 Fuel, ammunition & stores: 2,704 tons, 13.8 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   39,822 lbs / 18,063 Kg = 46.1 x 12.0 " / 305 mm shells or 8.5 torpedoes
 Stability (Unstable if below 1.00): 1.19
 Metacentric height 5.9 ft / 1.8 m
 Roll period: 15.6 seconds
 Steadiness - As gun platform (Average = 50 %): 82 %
   - Recoil effect (Restricted arc if above 1.00): 0.59
 Seaboat quality  (Average = 1.00): 1.65

Hull form characteristics:
 Hull has a flush deck,
   a normal bow and a cruiser stern
 Block coefficient (normal/deep): 0.544 / 0.553
 Length to Beam Ratio: 5.44 : 1
 'Natural speed' for length: 22.14 kts
 Power going to wave formation at top speed: 49 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 0.00 degrees
 Stern overhang: 0.00 ft / 0.00 m
 Freeboard (% = length of deck as a percentage of waterline length):
    Fore end,  Aft end
    - Forecastle: 20.00 %,  25.00 ft / 7.62 m,  22.00 ft / 6.71 m
    - Forward deck: 30.00 %,  22.00 ft / 6.71 m,  19.00 ft / 5.79 m
    - Aft deck: 35.00 %,  19.00 ft / 5.79 m,  18.00 ft / 5.49 m
    - Quarter deck: 15.00 %,  18.00 ft / 5.49 m,  18.00 ft / 5.49 m
    - Average freeboard:  19.97 ft / 6.09 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 64.2 %
  - Above water (accommodation/working, high = better): 137.1 %
 Waterplane Area: 30,604 Square feet or 2,843 Square metres
 Displacement factor (Displacement / loading): 117 %
 Structure weight / hull surface area: 162 lbs/sq ft or 790 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.91
  - Longitudinal: 2.45
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is excellent
 Room for accommodation and workspaces is excellent
 Ship has slow, easy roll, a good, steady gun platform
 Excellent seaboat, comfortable, can fire her guns in the heaviest weather