reveal: the house is a close replica of the Home house, of the base, in minecraft dungeons - the castle has also segments that have replicas of minecraft dungeons
Ship beachwreck and small sinkholes. The last one, is split into "dry" and "wet" sinkholes which are differently generated - wet ones i placed around the coast to be level with the ocean - dry ones generate on surface level and dent in the grass by 2-5 blocks at the time (had crazier ones, but they impacted the terrain at cliffs to crazy.. but i really liked them too as underground coves - needs more work)
other parts of the suggestions i temp to revisit at future maps :) (step by step)