What about the possibility to pvp ?

[Rygan]

Make poison skulls have really high dodge so that mages have to fight it and warriors can't touch it, even with 99 dex. Make Fire skulls have really high magic defense so that mages can't even touch them with lightning, even with 99 intelligence.

Then warriors and mages can work together without strife because they won't be stealing each other's exp and killing each others monsters.

You're forgetting a key aspect of mages: Spell components. Do you have any idea how hard it is to collect iron ore to convert into iron powder just to cast a lighting spell? How about amassing sulpher powder and ash? Mage attack spells are very expensive. What does a warrior have to do? Hit it with a stick over and over again.

There isn't a problem. If anything, mages have to work harder to level, because they have to avoid being hit and have to spend most of their game playing time farming for spell components. Which isn't too fun....

[Goku]

It will be easier for mages in the future from what I understand. When higher levels of magic come out you won't need components anymore.