A fast German destroyer minelayer

I am experimenting with the fast minelayer sketch designs on this one page of the Red Book. In one respect, I am pleased that a 36-knot destroyer minelayer is possible, but I had wanted more speed than that. What I called the Ger/DM/1915 design is simply the most completely specified ship on the page. There was no armament specified, so I thought 3-5in QF guns appropriate for a very large destroyer. We know that 6in guns are too large for small ships, so 5in seemed like a reasonable alternative. This is the Springsharp report:

Ger/DM/1915, Germany Destroyer Minelayer laid down 1915 (Engine 1950)

Displacement:
 2,688 t light; 2,764 t standard; 3,000 t normal; 3,189 t full load

Dimensions: Length overall / water x beam x draught
 421.31 ft / 420.00 ft x 40.00 ft x 20.00 ft (normal load)
 128.42 m / 128.02 m x 12.19 m  x 6.10 m

Armament:
      3 - 5.00" / 127 mm guns in single mounts, 62.50lbs / 28.35kg shells, 1915 Model
   Quick firing guns in deck mounts with hoists
   on centreline ends, majority forward, 2 raised mounts - superfiring
 Weight of broadside 188 lbs / 85 kg
 Shells per gun, main battery: 150

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 2 shafts, 68,746 shp / 51,284 Kw = 36.00 kts
 Range 4,200nm at 15.00 kts
 Bunker at max displacement = 425 tons

Complement:
 202 - 263

Cost:
 £0.471 million / $1.884 million

Distribution of weights at normal displacement:
 Armament: 23 tons, 0.8 %
 Machinery: 1,500 tons, 50.0 %
 Hull, fittings & equipment: 865 tons, 28.8 %
 Fuel, ammunition & stores: 312 tons, 10.4 %
 Miscellaneous weights: 300 tons, 10.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   748 lbs / 339 Kg = 12.0 x 5.0 " / 127 mm shells or 0.4 torpedoes
 Stability (Unstable if below 1.00): 1.16
 Metacentric height 1.7 ft / 0.5 m
 Roll period: 13.0 seconds
 Steadiness - As gun platform (Average = 50 %): 81 %
   - Recoil effect (Restricted arc if above 1.00): 0.31
 Seaboat quality  (Average = 1.00): 1.62

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.313
 Length to Beam Ratio: 10.50 : 1
 'Natural speed' for length: 20.49 kts
 Power going to wave formation at top speed: 61 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 3.00 degrees
 Stern overhang: 0.00 ft / 0.00 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  25.00 ft / 7.62 m
    - Forecastle (20 %): 22.00 ft / 6.71 m
    - Mid (50 %):  22.00 ft / 6.71 m (15.00 ft / 4.57 m aft of break)
    - Quarterdeck (15 %): 15.00 ft / 4.57 m
    - Stern:  15.00 ft / 4.57 m
    - Average freeboard: 18.74 ft / 5.71 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 178.2 %
  - Above water (accommodation/working, high = better): 180.5 %
 Waterplane Area: 10,502 Square feet or 976 Square metres
 Displacement factor (Displacement / loading): 79 %
 Structure weight / hull surface area: 37 lbs/sq ft or 181 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.43
  - Longitudinal: 2.87
  - Overall: 0.52
 Hull space for machinery, storage, compartmentation is cramped
 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