Please post your suggestions over in the Suggestions & Ideas subforum.

More building options, actual vertical ladders

animal powered crafting station, horse carriage, ships with animal slots, more legendary armor and weapons, bigger enemies (kraken?? i know there's a mod for it but prefer it implemented directly) frost giants, crypts or dungeon near shorelines or maybe in the middle of the ocean with serpents and serpent eggs inside

mistlands content and another biome,. because once mistlands comes out we are all going to get through it in like a day an be like wheres next content?

Mistlands content.

The merchant thing could be somewhat similar to the boss fights. The player would need specific 'valuables' to purchase the merchant's special items. Since gathering gold, etc. can be relatively commonplace after enough game hours the 'valuables' could be retrieved only after extra dangerous tasks as outlined by the trader. The merchant's special items might just be components for crafting unique showpieces but not functional upgrades.
"Dude, look at this ♥♥♥♥♥♥♥' lox saddle!"

As for a "real" answer, I'd like to note that there is an entire "Suggestions & Ideas" subforum for this sort of thing. On the forum index page, look at the right-hand column.

Some type of AI ship event. Ship AI attack on base and ship attack on the water.

i searched the wrong key word i guess. i didnt see what i searched so i wrote my own.

NPCs, world feels very empty