Here are some suggestions for additional options to gain more MP & XP:
MP & XPbooster: Add a MP Booster every weekdays or weekends, 100% MP Boost & 100% XP Boost.
MP & XP potions: These potions could be found in the game world or purchased in the in-game store. They would restore a certain amount of MP when consumed.
MP shrines: These shrines could be found in the game world. Activating them would give the player a temporary boost to their MP regeneration rate.
MP & XP challenges: These challenges could be completed to earn MP rewards.
More MP daily rewards: Players could receive a small amount of MP each day for logging in to the game.
I believe that these additions would give players more ways to gain more MP, which would make the game more enjoyable for everyone.