These are QOL Updates I believe the game would benefit from;
1. Slayer. The repetitiveness of the tasks are pretty frustrating imo. It's either Infernal Mage's, wild dogs or Magic Axe's. Would be improved with just a more diverse range of tasks.
2. Banking. The skillers out there would appreciate the withdraw all option as this would benefit things like cooking etc.
3. Thieving. The absolute bane of my existence. Lvl 1-60 if you're not clicking super efficient takes like 3-4 hours. Things like master farmers or a more variety of stalls between levels would help.