Is she diesel-powered? She has surface raider written all over her. If I were the Allied powers I wouldn't have let her be built either as she would have been superior to anything but the three RN battlecruisers if she got into the Atlantic, as with Deutscheland but worse. It also doesn't do to think what would have happened to the Exeter task force if they ran into her instead of Graf Spee.
There were certainly excellent WWI 30.5cm and 34cm designs on file so a modern 30.5cm gun would have been well within Krupp's capabilities. A modernized triple 30.5cm could have been based on the WWI model with a longer barrel and better elevation. Plus, according to NavWeps the Germans did improvements on shell design and elevation for older guns used for coastal defense.
http://www.navweaps.com/Weapons/WNGER_12-50_skc12.htm
With her additional size I wonder would she have the traditional excellent German "honeycomb" underwater protection? That had to be compromised with the Deutscheland class due to size restrictions. Also, would her armor be proof against 30.5cm guns or just 20.3cm like Deutscheland? I gathere there are few details available but it's something I imagine her designers would have looked at.
She also would be more than a match for the French light battleships, so the French would have had kittens over her.