Maybe one of the most annoying things in Classic/SoD wow is the cap of 20 quests.
This should be significantly higher.
The only issue would be the leveling strategy for phase/expansion releases of filling your quest log with 20 completed quests to hand in. There is an easy solution to avoid upsetting that strategy: Significant increase of cap for overall quest log - but utilize a cap of 20 for COMPLETED quests.