here is #8
Your boat will swim higher up in salt water, you can either put more gear on the boat to meet the cwl (construction water line), or you can lower this line the next time the boat is on the dry.
And #2 is special problem of glassfibre boats only:
I'm not sure about Richards #2. I'd say: Osmosis is seldom seen on boats in salt water. I've had a centerboarder on an inshore lake long time ago, that after years suffered Osmosis. I took care of a swedish double ender that has not had Osmosis for the time it was sitting in salt water (even brackish) of the western baltic sea for about 15 years. Then it was moved into a river environment ant it started to develope Osmosis pretty soon after.
My explanation: the gradient between freshwater outside and the "water" inside the is the driving force to dilute the solvent residues and it is higher, than in salt water: pure water outside and a high share of residues inside the laminate forces the water into the laminate for dilution. In saltwater you have no pure water outside, so the process of osmosis runs (more) in both direction.
So, I'd say, the saltier the water, the less the danger of catching this disease...
I must say I am far away from being a chemist and the process of Osmosis might be more complex... and maybe there is a chemist/sailor/boatbuilder on this forum who can say how things really are between the water outside our hulls and the moisture that is inside the grp-structure.