Ok, so the city is very dependant on import. That means it needs a lot of tradeships and also warships, because a blockade would be devastating. I think you need to add a lot of shipyards and drydocks
They would make some cool features...

Oh, and the forests on the island could be planted... the trees might make great masts and timber for ships. Yada, yada, yada

Also, you might consider adding some windmills on the cliffs (industrialisation for the win!).

And maybe add a fresh water well with a stream that drops into the ocean. Waterfalls are cool, you know