1: derricks: Just add some front and aft of the mast, like the two images above. Also you can use king-posts. These are small upright small masts either in front or aft of a cargo hatch with a derrick for cargo handling.
2: superstructure needs some breaks, a difference in height or width. Again look at the images provided, and also see other ships in the archive or the
merchant ships thread
3: too compressed means that it is too short, not enough for a ship with the length you have used. Again, study real life ships.
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Thank you Kim for the crest
"Never fear to try on something new. Remember that the Titanic was built by professionals, and the Ark by an amateur"