Speedy lock: where do you keep it?

I keep it in the hole for it on that end leaf but only the lock, the keys I keep with my jewelry so they don't get lost. I love the look of it w/ the lock and think the empty hole looks sad and like it's missing something.
 
I just bougth a speedy mini lin, and the lock turn kind of brown????? I got it at LV Cancun. So I dont know what to do, is it becuase the brown leather? are they supposed to look gold shinning all the time......advise please
 
I keep my lock on the outside of my damier speedy all the time, but i usually don't lock my mono speedy b/c I hate how it pulls the leaf down and makes it out of shape.
 
For those of you who keep your locks on the outside leaf... doesn't the lock turn the leather a darker shade?
I also heard that the lock stretches out the leaf.
Have you guys experienced this or not?