I'll give the Resto question a stab.
Fleet vessels have a workable lifetime, once they reach a certain age the costs involved to \"restore\" or in this case refit a vessel outweigh the costs of a new build. Take a vessels that's 40 years old and nearing it's lifespan. To completely gut the vessel, replace major amounts of steel and refit it with new wiring, replumb re+re generators,engines,pumps removal of hazardous material such as lead paint,asbestos etc... you are looking at a mojor amount of time and money.
Now look at a new build, as you are building it you are also fitting in new equipement and systems - major time savings and labour costs are way down. New, up to date materials are used and in the end you'll likely see very similar costs for both vessels yet the benefit is that you again have a vessel with a 40+ year lifespan.
Vessels get a yearly \"checkup\", and are constantly being maintained. But until you basically replace all of the infastructure it is not going to be able to keep up with new regulations and codes.
Ships wear out, they are constantly being abused by operators,patrons,vibrations,sea conditions,corrosion and about any other thing you can think of - they simply wear out.