1. Romance system for sure, but not locked to one character. I WANT MY HAREMS DAMMIT! ...Or at least the option to build one with the characters I can recruit/NPCs I interact with. Something to think about for the future at least. HAREMS FOR LIFE!!!!
2. Along with the idea or morality, I think having multiple ways to handle some quests would be pretty cool. Like through dialogue checks, the possession or absences of a certain item, or whether or not you fought/met/interacted with someone related to that quest/quest chain.
3. Party banter/chat/quests. Especially if you can mix and match who ends up in your party. Like at campsites or in town bars/inns. Something to add some variety to the game loop.
4. Hunts/Bounties. Y'know, to give players a reason to fight/grind/explore, like for money/loot/ related quests.
5. Landmarks. Things you can find and note down to better flesh out the world as maybe part of a quest or just a random reward for the intrepid adventurer who likes going off the beaten path.
6. A day/night system? Maybe to influence what ppl might say or what enemies you can fight? Maybe even when some quests can be taken?
Those are just some of the things I thought of... mostly because they are things I'd like to see in my own project.... But still things I'd like to se in more games like this more generally too. Anyway, best of luck and i'll definitely keep an eye on this project.