Ventilation and
insulation don't conflict except in the fact that you have to draw dry cold air in to displace hot moist air. Very necessary, as it is in a house.
Insulation will stop a lot of the
condensation that you are going to be battling daily. You must keep the air circulating constantly in all cabins and cabinets. Good fans are a must. Either a good
diesel fired forced air
heating system or diesel hydronic heating system will help although you can get by with a ventilated diesel stove and a good fan to circulate the heat. A diesel stove makes it more difficult to heat other cabins.
Computer fans mounted in the bulkheads of closets will help keep your cloths dry. There must be a vent for inlet air with the fan blowing out. Make sure the
hull is insulated in closets or your cloths will get wet and moldy. Insulate your hatches.
Hatches and Port-lights will get wet with condensation.
What else do you need to know?