Just random ideas, but here they are.
Make castle doors destroyable, but only when you're on kingdom mode, and only when a bunch of the same kingdom are on the island, so one person doesn't just come by and break down doors. Maybe have them come back after awhile or maybe even have to make a new one, doesn't matter.
Put card tables on the ferrys. They take forever to get to their destination, so why not pass the time with a little poker?
Make it so you can transmute rings together with alchemy. Not the strong ones, just the ones with one or two stat +'s, and not many times, say 2 rings together max, so you can get +4 speed rings or +1 strength and +2 constitution, but not keep adding combined rings together to get like +10 strength or +50 speed
:o
Make it so you can but the clothes as an item. I know it's been mentioned, but some of us like to be able to change what we look like whenever without having to run across the map several times to decide what we're wearing.
Uh thats it for now but I'll probably think of more later :P