There’s still room for kill quests in your game. Kill quests get a bad rap, but there’s nothing inherently wrong with them. They reward players for doing something they’re probably already doing, and rewarding players for doing things is good.
You can also improve a kill quest by doing something unique (e.g. herd some cows over the edge of a cliff to send them to their deaths) or by pairing them with another quest objective as an Optional/Bonus step or as a Choice between killing mobs or doing something else (e.g. destroying a hive).
You should also make sure to give a kill quest good context. “Kill 10 Bears because they looked at me funny” is not good context. “Kill 10 Invaders who are actively attacking my village” is much better context. Don’t shy away from using kill quests as a whole, just make sure you don’t use them too frequently (or as a crutch for poor imagination) and try to give them a little something extra if you can.
Remember the MMO Lesson series? It’s back now that I have some time on my hands. Check out the other MMO Lessons!