There never will be any balance if there are players with sets fully enchanted with rare/carus hearts, because this enchants are insanely strong.
We reached a point where rich (or farmers that abused the xmas quests with many chars) players "damaged the game" in a way that free players or new players will never be able to compete in pvp or pve with this players.
That can be solved, just deleting this hearts, and never add this quests event.
With this wipe, there should be also a compensation, because people actually used many moneys to obtain this hearts...I would say, for example, for each carus heart got wiped, 100kk or malls...(100kk is the in game price atm).
If you really want to balance the game, you should start working on this enchants..you can add any super strong enchants, but they will never compete with this hearts >.<