Many of the really big ships have pivoting propeller systems at the stern and horizontally mounted propellers in the bow to maneuver. As far as cranes, when I lived in Osaka, taking the train to Kobe goes along Osaka Bay and I remember seeing these super-massive floating cranes. To this day I wonder what kind of physics magic they use to stay afloat while lifting such monumental loads. Hats off to the engineers that make life so amazing.
Fun fact: HMM Algeciras is tied with MSC Gülsun (MSC) and Ever Ace (Evergreen) with a capacity 23,990 TEU, being the world's largest container ships. All of them are called "MegaMax" vessels because of their staggering capacity.
The company I worked for had the Seawise Giant on charter loading oil at Sullom Voe in the Shetlands. It was so large that when a giant wave hit its side the entire dock moved.
Another fun fact about the Zumwalt class. The 2 railguns at the front (Yes they are railguns and not just your regular 127mm naval guns) doesnt have any ammunition. At $35,000 per shell, the US navy wasn't keen on spending such a huge amount on ammunition for a prototype gun.
Those "incredibly powerful 6,700 horse power thrusters" are puny by naval standards. The diesel engines built into large ships routinely prodouce well over a hundred thousand shp(shaft horse power
