@CaptainManbeard
From the movies and books there is evidence that alot of Wizarding security is based around magic yeah, but we see Goblin security uses mechanical locks too.
But I would imagine that wards and barriers would be something he needs to work at as well. So his safe cracking would be part mechanical lock picking, magical lock picking and ward/barrier breaking as well.
So a little bit of both of column A, B C and D more or less.
True, but the mechanical locks usually require enchanted keys to open and probably have traps against simple lockpicking. Maybe your character has enchanted lockpicks that can trick some seals into thinking it's the right key or something XD. Maybe your character has also studied Goblin magic and technology extensively. To give two examples of enchanted locks, here's the Gringotts scene from Hogwarts Legacy, and the one from Deathly Hallows where the touch of a Gringotts employee unlocks the vault.