Making Pure Mesos in MapleStory

This. The only issue I can think of is it would be really difficult to survive first starting out without meso drops to buy pots and such.

An easy solution to this would be for new characters to get meso drops (perhaps 2-3x meso, since the mesos dropped by low level mobs is practically nothing and isn't really enough to buy pots with). When a character reaches level 60, everything stops dropping meso. This should allow for enough meso gain to buy pots, but make it much less worthwhile for botters to bother trying.

That sounds pretty absurd.
Where would a level 120+ get the meso needed to buy NLC potions? Not all classes have a self-healing skill, many still need actual potions that cost several thousand meso each.

Plus, this move would make meso worth a lot more - so a lot more worthwhile for botters. They have no problem making thousands of characters and leveling them 1-60 over and over and over again where the meso drop. Like all anti-botting strategies, you're hurting the legits while the bot-drivers are only slightly inconvenienced.