Artillery and mortar have 8 tiles range, but the battleship have only 5 tiles. This is very strange, for my opinion. Is on battleships we don`t have at least the same range of shooting? So, in reality naval guns have twice range from land.
I think, that naval units can have more ways to use with additional range. Not only defending land units on sea, but help them in landing with fire support.

If short ranges need for balance reason, so, make them decreasing damage if they further than 5 tiles (can be explained by decreasing accuracy while shooting big ranges).

OK, this was about guns on ships. But why, for example, rocket cruiser or nuclear submarine can`t carry the cruise missle, like this we have in modern ships. Maybe will be OK to block cruiser for 2 turns when rockets is loading on ship

Eh, Ironclad loses its usefulness when it comes to out of battle bombardment, which the Battleship is the only naval ships with the capacity to do so. But i get your frustrations related to inner sea mastodon