If you did the level up easy then you might have enough levels to do the Nocturnal Deadric Quest and get the Skeleton Key.... An Unbreakable Lockpick..... once you ahve this then you can open up every chest in Cyrodill
Except the ones that require a key.
There's always an exception to a rule.
Actually, for those that require a key, just use the console to unlock them.
And I didin't knew about that thanks.