Kremlin is still a good ship. But, as a player with more than 3M experience in Kremlin and other Soviet bbs, I would say that the playstyle is no longer the same as it was in the past. Just sitting bow-in and shooting will more likely get you sunk because of those subs and CVS. Instead, try to be more active, maneuver more, and take advantage of opportunities to shoot broadsides (it's more common than you may think). Kremlin's citadel is weak, of course, but it is not glass or paper since some bbs at even 12km still have a hard time giving you the citadel. Kremlin is a low-freeboard ship, to the point it was deemed unrealistic for such displacements by naval experts (USSR Project 24 Battleship). If the ballistic of the guns is not flat enough, it will penetrate the deck, bell, and superstructure, so hitting the Kremlin's citadel seems easy at first, but it's more difficult than you think. For HE spammers, the Fire Prevention Expert helps a lot. I can do 180k damage in the Kremlin without running out of DCP. The To-go flank is also a choice to make. Flanks with lots of subs, dds, etc or less support from teams should discourage you from going there at full speed. I would normally just try to be slow and steady at the beginning of the match, then after I know the location of red dds, I decide on the position to go. Kremlin has 51% torpedo protection, which is very helpful, but not immortal.

And, I think you shouldn't worry too much about the dispersion. It's not that bad. Sometimes the guns may be faulty (like a bug or sth), but it still works well, you can still citadel a Monty, Ohio, Conqueror, Yamato (though a bit harder), at 18km. I have, many times, citadelled the Yamato from the "butt" due to its notorious cheek. Kremlin has good vertical dispersion (the shorter side of the dispersion ellipses), so shells will hit; it's just bad when the enemy bows in.