The largest conventional warhead on a Russian cruise missile is 1000 kilos, give or take. The Tomahawk T-ASM carried a 454 kilo warhead for comparison.
Actually, in the 1980's the Russians tested the SS-N-24 "Scorpion" Supersonic long-range cruise missile. It carried two independently targeted nuclear warheads. It was a big mama of a missile and was to be carried on modified Yankee hulls.
A bit short and broad for a battlecruiser, I think. Stretch the hull and maybe thin it out a little, Get the most out of your engines. Perhaps a 10:1 length to beam ratio.
Jeez Alex, get away from the computer, stretch your legs, get another hobby, kiss a girl or something, you make the rest of us want to give up drawing.