When I first started touring I wouldn't leave my bike anywhere for fear of theft. Then I got bold. Very bold.

From my experience thieves don't spend a lot of time breaking bike locks when in an area with a lot of people around. They want to make it look like an owner unlocking a bike while they cut the lock. Anything taking longer that a minute, or using obvious tools attracts too much attention. Two locks of different types (coil and U-bolt) solve that. One lock must be attached to something that will not move. The other for the front wheel and frame.

As for pannier contents, I only carry an old camp stove and dirty clothing, so any thief would be welcome to that. My valuables are in the handlebar bag that I take with me.