Ixion, our club's lake is salt water, so I sail in it all the time. As Bob (Shipmate 60) pointed out, you just have to be on top of your maintenance. We have a washing table at the lake, with fresh water laid on, so we always wash down after each sail, then wipe down with a chamois. All my prop shafts are grease packed, so I don't have an issue there, but the rudder shafts need to be removed and greased occasionally to prevent brass to brass corrosion. In 5 years of operating in salt water I have only had one problem, and that was with a rudder shaft.
None of the paintwork on any of my models has been adversely affected by the salt water, but I believe that's because I am aware of the potential for damage, and make sure the boats are well cleaned after each outing.
Peter.