2% an hour? that's huge! and given the number of players with millions stashed away I can't see the benefit of this. If you had a million gold, and stashed it for 24 hours on compounding interest, you'd get over 250k. this will just flood the market with gold causing massive inflation.

If you borrowed the gold, there'd be absolutely nothing to stop you giving that gold to another player then deleting your account.

A guild bank, however... has some possibilities for trusted guildmembers, perhaps officers only.