The entire game is playable without the thievery skill up until you get the linder kemm vault quest. This really breaks immersion because the only way to get the vault key is from Kemm's attic and the only way to get into the attic is to get into Kemm's bedroom and the only non-thievery way to enter the bedroom (without pickpocketing kemm) is to smash the door down.
Smashing the door down completely breaks immersion since it's very loud and the guard patrolling would obviously hear you.
Please make a duplicate Kemm bedroom key "spare" and place it somewhere in the house. Also there badly needs to be a journal entry about finding a bedroom key since it is not at all intuitive of how a non-thief character would enter the vault. Most players don't even know the secret attic exists.