Unfortunately, i don't see this happening. as far as incentives for doing the quests, the biggest thing that makes people want to do them is the XP awarded, i myself have been able to gain quite a few levels just retracing and doing ones i've missed XD (and i've done every quest to completion up to my level except "The Circle Of Elements). Some give you some semi-decent gold, and others a few useful things from time to time.
One of the main reasons i don't see them changing rewards is that that would take tons of time, and leave those who've already done the quests without reward.
We also have the medal, which may not be a big incentive but it is there.
edit:
Also, even with a few points given to the player at certain levels or level ranges, it would be detrimental to the cows income, another reason i don't see it happening U.U
Dont get me wrong, id like to see more reasons to do quests other then to be a completionist XD
Edited by goolsby7, 15 August 2018 - 15:13.