I used and abused it for years. I got plenty of mileage out of those keys and chests, worry not. Don't hate that you can't think up creative ways to get ahead within the boundries of CF and I can.

I can still get into that chest I used to copy the key of as a thief solo, without advanced lockpick anyways. It didn't even slow gold gathering for my thieves. Creativity pays off. There are other thieves that are starting to catch on, and a couple I showed in person as Armagon.