reread my line about the lifeboats. I took the standards as when the rules before the titanic disaster. if I applied the later rules, you would have had room for about.... 150 people on board.
the ship would be more balanced if you had those holds always full. you won't have that in reality, so it does not work. anyways, you need that space for machinery, anyways
the cranes you added cannot actually reach the entire hold nor can they reach overboard with any load hanging under it. again, look at real life ships how they did that