KV-2 needs a defined role because currently it doesn't have one. It's not a damage sponge like Tiger and Churchill, doesn't have a good all around gun (also like tiger), it's not an artillery piece nor is it a siege weapon.
Simple and boring solution, make it an artillery piece like Priest. But I would like to see it as a true siege weapon in a manner like this:
It should set up and enter siege mode in friendly territory to be able to shoot, it also locks the territory down. Then, it should fire a big explosive shell (something like AVRE/Stiger) or an AT shell. The type of the shell is decided by the player. A manual and long reload is also needed.
Fix KV-2 and we're done. Supply drop is OK if you ask me.
it's basically a brummbar with a turret right now and actually works pretty well as that if you're careful with it (speaking from a non-balance preview point of view). the issue right now is that it's way to expensive for the performance it delivers.